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                                    ISO 8601

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        Current date and time expressed according to ISO 8601 [refresh]
   Date                 2022-04-13                
                        2022-04-13T08:03:41+00:00 
   Date and time in UTC 2022-04-13T08:03:41Z      
                        20220413T080341Z          
   Week                 2022-W15                  
   Week with weekday    2022-W15-3                
   Date without year    --04-13^[1]               
   Ordinal date         2022-103                  

   ISO 8601 is an international standard covering the worldwide exchange and
   communication of date- and time-related data. It is maintained by the
   Geneva-based International Organization for Standardization (ISO) and was
   first published in 1988, with updates in 1991, 2000, 2004, and 2019. The
   standard aims to provide a well-defined, unambiguous method of
   representing calendar dates and times in worldwide communications,
   especially to avoid misinterpreting numeric dates and times when such data
   is transferred between countries with different conventions for writing
   numeric dates and times.

   In general, ISO 8601 applies to these representations and formats: dates,
   in the Gregorian calendar (including the proleptic Gregorian calendar);
   times, based on the 24-hour timekeeping system, with optional UTC offset;
   time intervals; and combinations thereof.^[2] The standard does not assign
   specific meaning to any element of the dates/times represented: the
   meaning of any element depends on the context of its use. Dates and times
   represented cannot use words that do not have a specified numerical
   meaning within the standard (thus excluding names of years in the Chinese
   calendar), or that do not use computer characters (excludes images or
   sounds).^[2]

   In representations that adhere to the ISO 8601 interchange standard, dates
   and times are arranged such that the greatest temporal term (typically a
   year) is placed at the left and each successively lesser term is placed to
   the right of the previous term. Representations must be written in a
   combination of Arabic numerals and the specific computer characters (such
   as "-", ":", "T", "W", "Z") that are assigned specific meanings within the
   standard; that is, such commonplace descriptors of dates (or parts of
   dates) as "January", "Thursday", or "New Year's Day" are not allowed in
   interchange representations within the standard.

Contents

     * 1 History
     * 2 General principles
     * 3 Dates
          * 3.1 Years
          * 3.2 Calendar dates
          * 3.3 Week dates
          * 3.4 Ordinal dates
     * 4 Times
          * 4.1 Time zone designators
               * 4.1.1 Local time (unqualified)
               * 4.1.2 Coordinated Universal Time (UTC)
               * 4.1.3 Time offsets from UTC
     * 5 Combined date and time representations
     * 6 Durations
     * 7 Time intervals
          * 7.1 Repeating intervals
     * 8 Truncated representations
     * 9 Standardised extensions
     * 10 Usage
          * 10.1 Commerce
          * 10.2 RFCs
          * 10.3 Adoption as national standards
     * 11 See also
     * 12 Notes and references
     * 13 External links

History[edit]

   The first edition of the ISO 8601 standard was published as ISO 8601:1988
   in 1988. It unified and replaced a number of older ISO standards on
   various aspects of date and time notation: ISO 2014, ISO 2015, ISO 2711,
   ISO 3307, and ISO 4031.^[3] It has been superseded by a second edition
   ISO 8601:2000 in 2000, by a third edition ISO 8601:2004 published on 1
   December 2004, and withdrawn and revised by ISO 8601-1:2019 and
   ISO 8601-2:2019 on 25 February 2019. ISO 8601 was prepared by,^[4] and is
   under the direct responsibility of, ISO Technical Committee TC 154.^[5]

   ISO 2014, though superseded, is the standard that originally introduced
   the all-numeric date notation in most-to-least-significant order
   [YYYY]-[MM]-[DD]. The ISO week numbering system was introduced in
   ISO 2015, and the identification of days by ordinal dates was originally
   defined in ISO 2711.

   Issued in February 2019, the fourth revision of the standard ISO
   8601-1:2019 represents slightly updated contents of the previous ISO
   8601:2004 standard,^[6]^[7] whereas the new ISO 8601-2:2019 defines
   various extensions such as uncertainties or parts of the Extended
   Date/Time Format (EDTF).^[8]^[9]^[10]^[11]^[12]^[13]

                         History of published editions
   Name                     Description                                       
                            Data elements and interchange formats —           
   ISO 8601:1988            Information interchange — Representation of dates 
                            and times                                         
                            Data elements and interchange formats —           
   ISO 8601:1988/COR 1:1991 Information interchange — Representation of dates 
                            and times — Technical Corrigendum 1               
                            Data elements and interchange formats —           
   ISO 8601:2000            Information interchange — Representation of dates 
                            and times                                         
                            Data elements and interchange formats —           
   ISO 8601:2004            Information interchange — Representation of dates 
                            and times                                         
   ISO 8601-1:2019          Date and time — Representations for information   
                            interchange — Part 1: Basic rules                 
   ISO 8601-2:2019          Date and time — Representations for information   
                            interchange — Part 2: Extensions                  

General principles[edit]

     * Date and time values are ordered from the largest to smallest unit of
       time: year, month (or week), day, hour, minute, second, and fraction
       of second. The lexicographical order of the representation thus
       corresponds to chronological order, except for date representations
       involving negative years or time offset. This allows dates to be
       naturally sorted by, for example, file systems.
     * Each date and time value has a fixed number of digits that must be
       padded with leading zeros.
     * Representations can be done in one of two formats – a basic format
       with a minimal number of separators or an extended format with
       separators added to enhance human readability.^[14]^[15] The standard
       notes that "The basic format should be avoided in plain text."^[16]
       The separator used between date values (year, month, week, and day) is
       the hyphen, while the colon is used as the separator between time
       values (hours, minutes, and seconds). For example, the 6th day of the
       1st month of the year 2009 may be written as "2009-01-06" in the
       extended format or simply as "20090106" in the basic format without
       ambiguity.
     * For reduced precision,^[17] any number of values may be dropped from
       any of the date and time representations, but in the order from the
       least to the most significant. For example, "2004-05" is a valid ISO
       8601 date, which indicates May (the fifth month) 2004. This format
       will never represent the 5th day of an unspecified month in 2004, nor
       will it represent a time-span extending from 2004 into 2005.
     * If necessary for a particular application, the standard supports the
       addition of a decimal fraction to the smallest time value in the
       representation.

Dates[edit]

                                   April 2022
   Week      Mon       Tue       Wed      Thu      Fri      Sat      Sun      
   W13       28        29        30       31       01       02       03       
   W14       04        05        06       07       08       09       10       
   W15       11        12        13       14       15       16       17       
   W16       18        19        20       21       22       23       24       
   W17       25        26        27       28       29       30       01       

   The standard uses the Gregorian calendar, which "serves as an
   international standard for civil use."^[18]

   ISO 8601:2004 fixes a reference calendar date to the Gregorian calendar of
   20 May 1875 as the date the Convention du Mètre (Metre Convention) was
   signed in Paris (the explicit reference date was removed in ISO
   8601-1:2019). However, ISO calendar dates before the convention are still
   compatible with the Gregorian calendar all the way back to the official
   introduction of the Gregorian calendar on 15 October 1582.

   Earlier dates, in the proleptic Gregorian calendar, may be used by mutual
   agreement of the partners exchanging information. The standard states that
   every date must be consecutive, so usage of the Julian calendar would be
   contrary to the standard (because at the switchover date, the dates would
   not be consecutive).

  Years[edit]

   YYYY   
   ±YYYYY 

   ISO 8601 prescribes, as a minimum, a four-digit year [YYYY] to avoid the
   year 2000 problem. It therefore represents years from 0000 to 9999, year
   0000 being equal to 1 BC and all others AD. However, years before 1583 are
   not automatically allowed by the standard. Instead "values in the range
   [0000] through [1582] shall only be used by mutual agreement of the
   partners in information interchange."^[19]

   To represent years before 0000 or after 9999, the standard also permits
   the expansion of the year representation but only by prior agreement
   between the sender and the receiver.^[20] An expanded year representation
   [±YYYYY] must have an agreed-upon number of extra year digits beyond the
   four-digit minimum, and it must be prefixed with a + or − sign^[21]
   instead of the more common AD/BC (or CE/BCE) notation; by convention 1 BC
   is labelled +0000, 2 BC is labeled −0001, and so on.^[22]

  Calendar dates[edit]

   YYYY-MM-DD                                        or   YYYYMMDD    
   YYYY-MM                                           (but not YYYYMM)
   Only allowed in the superseded version from 2000: 
   --MM-DD                                           or   --MMDD^[1]  

   Calendar date representations are in the form shown in the adjacent box.
   [YYYY] indicates a four-digit year, 0000 through 9999. [MM] indicates a
   two-digit month of the year, 01 through 12. [DD] indicates a two-digit day
   of that month, 01 through 31. For example, "5 April 1981" may be
   represented as either "1981-04-05"^[14] in the extended format or
   "19810405" in the basic format.

   The standard also allows for calendar dates to be written with reduced
   precision. For example, one may write "1981-04" to mean "1981 April". The
   2000 version allowed writing "--04-05" to mean "April 5"^[23] but the 2004
   version does not allow omitting the year when a month is present. One may
   simply write "1981" to refer to that year, "198" to refer to the decade
   from 1980 to 1989 inclusive, or "19" to refer to the century from 1900 to
   1999 inclusive. Although the standard allows both the "YYYY-MM-DD" and
   YYYYMMDD formats for complete calendar date representations, if the day
   [DD] is omitted then only the YYYY-MM format is allowed. By disallowing
   dates of the form YYYYMM, the standard avoids confusion with the truncated
   representation YYMMDD (still often used).

  Week dates[edit]

   Main article: ISO week date

   YYYY-Www   or YYYYWww  
   YYYY-Www-D or YYYYWwwD 

   Week date representations are in the formats as shown in the adjacent box.
   [YYYY] indicates the ISO week-numbering year which is slightly different
   from the traditional Gregorian calendar year (see below). [Www] is the
   week number prefixed by the letter W, from W01 through W53. [D] is the
   weekday number, from 1 through 7, beginning with Monday and ending with
   Sunday.

   There are several mutually equivalent and compatible descriptions of week
   01:

     * the week with the first business day in the starting year (considering
       that Saturdays, Sundays and 1st January are non-working days),
     * the week with the starting year's first Thursday in it (the formal ISO
       definition),
     * the week with 4 January in it,
     * the first week with the majority (four or more) of its days in the
       starting year, and
     * the week starting with the Monday in the period 29 December - 4
       January.

   As a consequence, if 1 January is on a Monday, Tuesday, Wednesday or
   Thursday, it is in week 01. If 1 January is on a Friday, Saturday or
   Sunday, it is in week 52 or 53 of the previous year (there is no week 00).
   28 December is always in the last week of its year.

   The week number can be described by counting the Thursdays: week 12
   contains the 12th Thursday of the year.

   The ISO week-numbering year starts at the first day (Monday) of week 01
   and ends at the Sunday before the new ISO year (hence without overlap or
   gap). It consists of 52 or 53 full weeks. The first ISO week of a year may
   have up to three days that are actually in the Gregorian calendar year
   that is ending; if three, they are Monday, Tuesday and Wednesday.
   Similarly, the last ISO week of a year may have up to three days that are
   actually in the Gregorian calendar year that is starting; if three, they
   are Friday, Saturday, and Sunday. The Thursday of each ISO week is always
   in the Gregorian calendar year denoted by the ISO week-numbering year.

   Examples:

     * Monday 29 December 2008 is written "2009-W01-1"
     * Sunday 3 January 2010 is written "2009-W53-7"

  Ordinal dates[edit]

   YYYY-DDD or YYYYDDD 

   An ordinal date is a simple form for occasions when the arbitrary nature
   of week and month definitions are more of an impediment than an aid, for
   instance, when comparing dates from different calendars. As represented
   above, [YYYY] indicates a year. [DDD] is the day of that year, from 001
   through 365 (366 in leap years). For example, "1981-04-05" is also
   "1981-095".

   This format is used with simple hardware systems that have a need for a
   date system, but where including full calendar calculation software may be
   a significant nuisance. This system is sometimes referred to as "Julian
   Date", but this can cause confusion with the astronomical Julian day, a
   sequential count of the number of days since day 0 beginning 1 January
   4713 BC Greenwich noon, Julian proleptic calendar (or noon on ISO date
   −4713-11-24 which uses the Gregorian proleptic calendar with a year 0000).

Times[edit]

   Thh:mm:ss.sss or Thhmmss.sss 
   Thh:mm:ss     or Thhmmss     
   Thh:mm        or Thhmm       
   Thh           

   ISO 8601 uses the 24-hour clock system. As of ISO 8601-1:2019, the basic
   format is T[hh][mm][ss] and the extended format is T[hh]:[mm]:[ss].
   Earlier versions omitted the T (representing time) in both formats.

     * [hh] refers to a zero-padded hour between 00 and 23.
     * [mm] refers to a zero-padded minute between 00 and 59.
     * [ss] refers to a zero-padded second between 00 and 60 (where 60 is
       only used to denote an added leap second).

   So a time might appear as either "T134730" in the basic format or
   "T13:47:30" in the extended format. ISO 8601-1:2019 allows the T to be
   omitted in the extended format, as in "13:47:30", but only allows the T to
   be omitted in the basic format when there is no risk of ambiguity with
   date expressions.

   Either the seconds, or the minutes and seconds, may be omitted from the
   basic or extended time formats for greater brevity but decreased
   precision; the resulting reduced precision time formats are:^[24]

     * T[hh][mm] in basic format or [hh]:[mm] in extended format, when
       seconds are omitted.
     * T[hh], when both seconds and minutes are omitted.

   As of ISO 8601-1:2019 midnight may only be referred to as "00:00",
   corresponding to the beginning of a calendar day. Earlier versions of the
   standard allowed "24:00" corresponding to the end of a day, but this is
   explicitly disallowed by the 2019 revision.

   A decimal fraction may be added to the lowest order time element present,
   in any of these representations. A decimal mark, either a comma or a dot
   (following ISO 80000-1 according to ISO 8601:1-2019,^[25] which does not
   stipulate a preference except within International Standards, but with a
   preference for a comma according to ISO 8601:2004)^[26] is used as a
   separator between the time element and its fraction. To denote "14 hours,
   30 and one half minutes", do not include a seconds figure. Represent it as
   "14:30,5", "T1430,5", "14:30.5", or "T1430.5". There is no limit on the
   number of decimal places for the decimal fraction. However, the number of
   decimal places needs to be agreed to by the communicating parties. For
   example, in Microsoft SQL Server, the precision of a decimal fraction is 3
   for a DATETIME, i.e., "yyyy-mm-ddThh:mm:ss[.mmm]".^[27]

  Time zone designators[edit]

   <time>Z      
   <time>±hh:mm 
   <time>±hhmm  
   <time>±hh    

   Time zones in ISO 8601 are represented as local time (with the location
   unspecified), as UTC, or as an offset from UTC.

    Local time (unqualified)[edit]

   If no UTC relation information is given with a time representation, the
   time is assumed to be in local time. While it may be safe to assume local
   time when communicating in the same time zone, it is ambiguous when used
   in communicating across different time zones. Even within a single
   geographic time zone, some local times will be ambiguous if the region
   observes daylight saving time. It is usually preferable to indicate a time
   zone (zone designator) using the standard's notation.

    Coordinated Universal Time (UTC)[edit]

   If the time is in UTC, add a Z directly after the time without a space. Z
   is the zone designator for the zero UTC offset. "09:30 UTC" is therefore
   represented as "09:30Z" or "T0930Z". "14:45:15 UTC" would be "14:45:15Z"
   or "T144515Z".

   The Z suffix in the ISO 8601 time representation is sometimes referred to
   as "Zulu time" because the same letter is used to designate the Zulu time
   zone. However the ACP 121 standard that defines the list of military time
   zones makes no mention of UTC and derives the "Zulu time" from the
   Greenwich Mean Time^[28] which was formerly used as the international
   civil time standard. GMT is no longer precisely defined by the scientific
   community and can refer to either UTC or UT1 depending on context.^[29]

    Time offsets from UTC[edit]

   The UTC offset is appended to the time in the same way that 'Z' was above,
   in the form ±[hh]:[mm], ±[hh][mm], or ±[hh].

   Negative UTC offsets describe a time zone west of UTC±00:00, where the
   civil time is behind (or earlier) than UTC so the zone designator will
   look like "−03:00","−0300", or "−03".

   Positive UTC offsets describe a time zone at or east of UTC±00:00, where
   the civil time is the same as or ahead (or later) than UTC so the zone
   designator will look like "+02:00","+0200", or "+02".

   Examples

     * "−05:00" for New York on standard time (UTC-05:00)
     * "−04:00" for New York on daylight saving time (UTC-04:00)
     * "+00:00" (but not "−00:00") for London on standard time (UTC±00:00)
     * "+02:00" for Cairo (UTC+02:00)
     * "+05:30" for Mumbai (UTC+05:30)
     * "+14:00" for Kiribati (UTC+14:00)

   See List of UTC time offsets for other UTC offsets.

   To represent a negative offset, ISO 8601 specifies using a minus sign. If
   the interchange character set is limited and does not have a minus sign
   character, then the hyphen-minus should be used. ASCII does not have a
   minus sign, so its hyphen-minus character (code is 45 decimal or 2D
   hexadecimal) would be used. If the character set has a minus sign, then
   that character should be used. Unicode has a minus sign, and its character
   code is U+2212 (2212 hexadecimal); the HTML character entity invocation is
   &minus;.

   The following times all refer to the same moment: "18:30Z", "22:30+04",
   "1130−0700", and "15:00−03:30". Nautical time zone letters are not used
   with the exception of Z. To calculate UTC time one has to subtract the
   offset from the local time, e.g. for "15:00−03:30" do 15:00 − (−03:30) to
   get 18:30 UTC.

   An offset of zero, in addition to having the special representation "Z",
   can also be stated numerically as "+00:00", "+0000", or "+00". However, it
   is not permitted to state it numerically with a negative sign, as
   "−00:00", "−0000", or "−00". The section dictating sign usage^[30] states
   that a plus sign must be used for a positive or zero value, and a minus
   sign for a negative value. Contrary to this rule, RFC 3339, which is
   otherwise a profile of ISO 8601, permits the use of "-00", with the same
   denotation as "+00" but a differing connotation.^[31]^[32]

Combined date and time representations[edit]

   <date>T<time> 

   A single point in time can be represented by concatenating a complete date
   expression, the letter "T" as a delimiter, and a valid time expression.
   For example, "2007-04-05T14:30". In ISO 8601:2004 it was permitted to omit
   the "T" character by mutual agreement as in "200704051430",^[33] but this
   provision was removed in ISO 8601-1:2019. Separating date and time parts
   with other characters such as space is not allowed in ISO 8601, but
   allowed in its profile RFC 3339.^[34]

   If a time zone designator is required, it follows the combined date and
   time. For example, "2007-04-05T14:30Z" or "2007-04-05T12:30−02:00".

   Either basic or extended formats may be used, but both date and time must
   use the same format. The date expression may be calendar, week, or
   ordinal, and must use a complete representation. The time may be
   represented using a specified reduced precision format.

Durations[edit]

   PnYnMnDTnHnMnS 
   PnW            
   P<date>T<time> 

   Durations define the amount of intervening time in a time interval and are
   represented by the format P[n]Y[n]M[n]DT[n]H[n]M[n]S or P[n]W as shown on
   the aside. In these representations, the [n] is replaced by the value for
   each of the date and time elements that follow the [n]. Leading zeros are
   not required, but the maximum number of digits for each element should be
   agreed to by the communicating parties. The capital letters P, Y, M, W, D,
   T, H, M, and S are designators for each of the date and time elements and
   are not replaced.

     * P is the duration designator (for period) placed at the start of the
       duration representation.
          * Y is the year designator that follows the value for the number of
            calendar years.
          * M is the month designator that follows the value for the number
            of calendar months.
          * W is the week designator that follows the value for the number of
            weeks.
          * D is the day designator that follows the value for the number of
            calendar days.
     * T is the time designator that precedes the time components of the
       representation.
          * H is the hour designator that follows the value for the number of
            hours.
          * M is the minute designator that follows the value for the number
            of minutes.
          * S is the second designator that follows the value for the number
            of seconds.

   For example, "P3Y6M4DT12H30M5S" represents a duration of "three years, six
   months, four days, twelve hours, thirty minutes, and five seconds".

   Date and time elements including their designator may be omitted if their
   value is zero, and lower-order elements may also be omitted for reduced
   precision. For example, "P23DT23H" and "P4Y" are both acceptable duration
   representations. However, at least one element must be present, thus "P"
   is not a valid representation for a duration of 0 seconds. "PT0S" or
   "P0D", however, are both valid and represent the same duration.

   To resolve ambiguity, "P1M" is a one-month duration and "PT1M" is a
   one-minute duration (note the time designator, T, that precedes the time
   value). The smallest value used may also have a decimal fraction,^[35] as
   in "P0.5Y" to indicate half a year. This decimal fraction may be specified
   with either a comma or a full stop, as in "P0,5Y" or "P0.5Y". The standard
   does not prohibit date and time values in a duration representation from
   exceeding their "carry over points" except as noted below. Thus, "PT36H"
   could be used as well as "P1DT12H" for representing the same duration. But
   keep in mind that "PT36H" is not the same as "P1DT12H" when switching from
   or to Daylight saving time.

   Alternatively, a format for duration based on combined date and time
   representations may be used by agreement between the communicating parties
   either in the basic format PYYYYMMDDThhmmss or in the extended format
   P[YYYY]-[MM]-[DD]T[hh]:[mm]:[ss]. For example, the first duration shown
   above would be "P0003-06-04T12:30:05". However, individual date and time
   values cannot exceed their moduli (e.g. a value of 13 for the month or 25
   for the hour would not be permissible).^[36]

   The standard describes a duration as part of time intervals, which are
   discussed in the next section. The duration format on its own is ambiguous
   regarding the total number of days in a calendar year and calendar month.
   The number of seconds in a calendar day is also ambiguous because of leap
   seconds. For example "P1M" on its own could be 28, 29, 30, or 31 days.
   There is no ambiguity when used in a time interval. Using example "P2M"
   duration of two calendar months:

     * interval 2003-02-15T00:00:00Z/P2M ends two calendar months later at
       2004-03-15T00:00:00Z which is 59 days later
     * interval 2003-07-15T00:00:00Z/P2M ends two calendar months later at
       2004-03-15T00:00:00Z which is 62 days later

   The duration format (or a subset thereof) is widely used independent of
   time intervals, as with the Java 8 Duration class which supports a subset
   of the duration format.^[37]^[38]

Time intervals[edit]

   <start>/<end>      
   <start>/<duration> 
   <duration>/<end>   
   <duration>         

   A time interval is the intervening time between two time points. The
   amount of intervening time is expressed by a duration (as described in the
   previous section). The two time points (start and end) are expressed by
   either a combined date and time representation or just a date
   representation.

   There are four ways to express a time interval:

    1. Start and end, such as "2007-03-01T13:00:00Z/2008-05-11T15:30:00Z"
    2. Start and duration, such as "2007-03-01T13:00:00Z/P1Y2M10DT2H30M"
    3. Duration and end, such as "P1Y2M10DT2H30M/2008-05-11T15:30:00Z"
    4. Duration only, such as "P1Y2M10DT2H30M", with additional context
       information

   Of these, the first three require two values separated by an interval
   designator which is usually a solidus (more commonly referred to as a
   forward slash "/"). Section 3.2.6 of ISO 8601-1:2019 notes that "A solidus
   may be replaced by a double hyphen ["--"] by mutual agreement of the
   communicating partners", and previous versions used notations like
   "2000--2002".^[39] Use of a double hyphen instead of a solidus allows
   inclusion in computer filenames;^[40] in common operating systems, a
   solidus is a reserved character and is not allowed in a filename.

   For <start>/<end> expressions, if any elements are missing from the end
   value, they are assumed to be the same as for the start value including
   the time zone. This feature of the standard allows for concise
   representations of time intervals. For example, the date of a two-hour
   meeting including the start and finish times could be simply shown as
   "2007-12-14T13:30/15:30", where "/15:30" implies "/2007-12-14T15:30" (the
   same date as the start), or the beginning and end dates of a monthly
   billing period as "2008-02-15/03-14", where "/03-14" implies "/2008-03-14"
   (the same year as the start).

   If greater precision is desirable to represent the time interval, then
   more time elements can be added to the representation. An interval denoted
   "2007-11-13/15" can start at any time on 2007-11-13 and end at any time on
   2007-11-15, whereas "2007-11-13T09:00/15T17:00" includes the start and end
   times. To explicitly include all of the start and end dates, the interval
   would be represented as "2007-11-13T00:00/16T00:00".

  Repeating intervals[edit]

   Rn/<interval> 
   R/<interval>  

   Repeating intervals are specified in clause "4.5 Recurring time interval".
   They are formed by adding "R[n]/" to the beginning of an interval
   expression, where R is used as the letter itself and [n] is replaced by
   the number of repetitions. Leaving out the value for [n] or specifying a
   value of -1, means an unbounded number of repetitions. A value of 0 for
   [n] means the interval is not repeated.

   If the interval specifies the start (forms 1 and 2 above), then this is
   the start of the repeating interval. If the interval specifies the end but
   not the start (form 3 above), then this is the end of the repeating
   interval. For example, to repeat the interval of "P1Y2M10DT2H30M" five
   times starting at "2008-03-01T13:00:00Z", use
   "R5/2008-03-01T13:00:00Z/P1Y2M10DT2H30M".

Truncated representations[edit]

   ISO 8601:2000 allowed truncation (by agreement), where leading components
   of a date or time are omitted. Notably, this allowed two-digit years to be
   used and the ambiguous formats YY-MM-DD and YYMMDD. This provision was
   removed in ISO 8601:2004.

                           Truncated representations
   Type                               Basic format Basic   Extended Extended  
                                                   example format   example   
   A specific date in the implied     YYMMDD       851026  YY-MM-DD 85-10-26  
   century                            
   A specific year and month in the   -YYMM        -8510   -YY-MM   -85-10    
   implied century                    
   A specific year in the implied     -YY          -85     N/A      
   century                            
   A specific day of a month in the   --MMDD       --1026  --MM-DD  --10-26   
   implied year                       
   A specific month in the implied    --MM         --10             
   year                                                    N/A
   A specific day in the implied      ---DD        ---26   
   month                              

   Only the first type (specific date in the implied century) omits the
   leading - for century. All other formats have one leading - per omitted
   century, year, and month.

Standardised extensions[edit]

   ISO 8601-2:2019 defines a set of standardised extensions to the ISO 8601
   date and time formats.

   Extended Date/Time Format (EDTF)
           The EDTF is given as an example of a profile of ISO 8601. Some of
           its features are:^[8]
              * Uncertain and approximate qualifiers, '?' and '~', as well as
                their combined used, '%'; they can be applied to the whole
                date or to individual components.
              * Time intervals with an open (unbounded) end or an unknown
                end.
              * Exponential and significant figure notation in years.
              * Special "month" values indicating sub-year groupings such as
                seasons and quarters.
              * Syntax for serializing a list of dates.
           The EDTF features are described in the "Date and Time Extensions"
           section of ISO 8601-2:2019.

   Repeat rules for recurring time intervals
           ISO 8601-2:2019 also defines a format to constrain repeating
           intervals based on syntax from iCalendar.

Usage[edit]

   On the Internet, the World Wide Web Consortium (W3C) uses the IETF
   standard based on ISO 8601 in defining a profile of the standard that
   restricts the supported date and time formats to reduce the chance of
   error and the complexity of software. The very simple specification is
   based on a draft of the RFC 3339 mentioned below.^[41]

   ISO 8601 is referenced by several specifications, but the full range of
   options of ISO 8601 is not always used. For example, the various
   electronic program guide standards for TV, digital radio, etc. use several
   forms to describe points in time and durations. The ID3 audio meta-data
   specification also makes use of a subset of ISO 8601.^[42] The X.690
   encoding standard's GeneralizedTime makes use of another subset of ISO
   8601.

  Commerce[edit]

   The ISO 8601 week date, as of 2006, appeared in its basic form on major
   brand commercial packaging in the United States. Its appearance depended
   on the particular packaging, canning, or bottling plant more than any
   particular brand. The format is particularly useful for quality assurance,
   so that production errors can be readily traced to work weeks, and
   products can be correctly targeted for recall.

  RFCs[edit]

   IETF RFC 3339^[43] defines a profile of ISO 8601 for use in Internet
   protocols and standards. It explicitly excludes durations and dates before
   the common era. The more complex formats such as week numbers and ordinal
   days are not permitted.^[44]

   RFC 3339 deviates from ISO 8601 in allowing a zero time zone offset to be
   specified as "-00:00", which ISO 8601 forbids. RFC 3339 intends "-00:00"
   to carry the connotation that it is not stating a preferred time zone,
   whereas the conforming "+00:00" or any non-zero offset connotes that the
   offset being used is preferred. This convention regarding "-00:00" is
   derived from earlier RFCs, such as RFC 2822 which uses it for timestamps
   in email headers. RFC 2822 made no claim that any part of its timestamp
   format conforms to ISO 8601, and so was free to use this convention
   without conflict.

  Adoption as national standards[edit]

   Australia          AS/NZS ISO 8601.1:2021, AS/NZS ISO 8601.2:2021          
                      (replaced AS ISO 8601-2007)                             
   Austria            ÖNORM ISO 8601 (replaced ÖNORM EN 28601)                
   Belgium            NBN EN 28601 (1993)                                     
   Brazil             NBR 5892:2019                                           
   Canada             CAN/CSA-Z234.4-89 (R2007)^[45]                          
   Colombia           NTC 1034:2014 Source ICONTEC (This standard is          
                      identical to ISO 8601:2004)                             
   China              GB/T 7408-2005                                          
   Czech Republic     ČSN ISO 8601 (replaced ČSN EN 28601)                    
   Denmark            DS/ISO 8601:2005 (replaced DS/EN 28601)                 
   Estonia            EVS 8:2008; EVS-ISO 8601:2011                           
   European Norm      EN ISO 8601, EN 28601:1992 (cancelled 7 October 2011)   
   Finland            SFS-EN 28601                                            
   France             NF Z69-200; NF EN 28601:1993-06-01 (cancelled)          
                      DIN ISO 8601:2006-09 (replaced DIN EN 28601:1993-02);   
   Germany            related: DIN 5008:2011-04 (replaced DIN 5008:2005-05,   
                      DIN 5008:2001-11, DIN 5008:1996-05)                     
   Greece             ELOT EN 28601                                           
   Hungary            MSZ ISO 8601:2003                                       
   Iceland            IST EN 28601:1992 (obsolete)                            
   India              IS 7900:2001                                            
   Ireland            IS/EN 28601:1993                                        
   Italy              UNI EN 28601 (1993)                                     
   Japan              JIS X 0301:2002                                         
   Korea, Republic of KS X ISO 8601                                           
   Lithuania          LST ISO 8601:2006 (replaced LST ISO 8601:1997)          
   Luxembourg         ITM-EN 28601                                            
   Mexico             NMX-CH-150-IMNC-1999^[46]                               
   Netherlands        NEN ISO 8601, NEN EN 28601 (1994), NEN 2772             
   Norway             NS-ISO 8601                                             
   Poland             PN-EN 28601:2002 (Obsolete as of 2008. No standard was  
                      given in exchange.^[47])                                
   Portugal           NP EN 28601                                             
   Russia             ГОСТ ИСО 8601-2001 (current), ГОСТ 7.64-90 (obsolete)   
   South Africa       SANS 8601:2009^[48]                                     
   Spain              UNE EN 28601:1995                                       
   Sweden             SS-ISO 8601:2011 (Approved 2011-11-01, replaces SS-ISO  
                      8601)                                                   
   Switzerland        SN ISO 8601:2005-08 (replaced SN-EN 28601:1994)         
   Taiwan             CNS 7648                                                
   Thailand           TIS 1111:2535 (1992)                                    
   Turkey             TS ISO 8601                                             
   Ukraine            ДСТУ ISO 8601:2010                                      
   United Kingdom     BS ISO 8601:2004, BS EN 28601 (1989-06-30)              
   United States      ANSI INCITS 30-1997 (R2008) and NIST FIPS PUB 4-2       
   Vietnam            TCVN 6398-1:1998                                        

See also[edit]

     * Astronomical year numbering
     * Date and time representation by country
     * Date format by country
     * Horology

Notes and references[edit]

    1. ^ ^a ^b last in ISO 8601:2000, in use by "RFC 6350 - vCard Format
       Specification". IETF. August 2011. Archived from the original on
       2016-05-31. Retrieved 2021-01-21. Truncated representation, as
       specified in [ISO.8601.2000], Sections 5.2.1.3 d), e), and f), is
       permitted., although removed in ISO 8601:2004
    2. ^ ^a ^b ISO 8601:2004[E] section 1 Scope
    3. ^
       Link: mw-deduplicated-inline-style
       ISO 8601:2004(E), ISO, 2004-12-01, Annex A: ... From that concept
       representations of all other date and time values were logically
       derived; thus, ISO 2014, ISO 3307 and ISO 4031 have been superseded.
       ... Identification of a particular date by means of ordinal dates
       (ISO 2711) and by means of the week numbering system (ISO 2015) were
       alternative methods that the basic concept of this International
       Standard could also encompass; thus, ISO 2015 and ISO 2711 have now
       been superseded.
    4. ^
       Link: mw-deduplicated-inline-style
       ISO 8601:2004(E). ISO. 2004-12-01. p. iv Foreword.
    5. ^
       Link: mw-deduplicated-inline-style
       "TC 154 Processes, data elements and documents in commerce, industry
       and administration". Technical committees. ISO. Archived from the
       original on 2016-05-25. Retrieved 2014-08-16.
    6. ^
       Link: mw-deduplicated-inline-style
       "ISO/DIS 8601-1:2016-10-26" (PDF). Library of Congress. Archived from
       the original (PDF) on 2017-10-19.
    7. ^
       Link: mw-deduplicated-inline-style
       "German draft E DIN ISO 8601-1:2017-02 Datenelemente und
       Austauschformate - Informationsaustausch - Darstellung von Datum und
       Uhrzeit - Teil 1: Grundlegende Regeln (ISO/DIS 8601-1:2016)".
       DIN-Normenausschuss Informationstechnik und Anwendungen (NIA).
       Archived from the original on 2017-10-20. Retrieved 2017-10-19.
    8. ^ ^a ^b
       Link: mw-deduplicated-inline-style
       "Extended Date/Time Format (EDTF) Specification". The Library of
       Congress. 2019-10-08 [2019-02-04, 2014, 2012]. Archived from the
       original on 2020-03-07. Retrieved 2020-03-07.
    9. ^
       Link: mw-deduplicated-inline-style
       "Extended Date/Time Format (EDTF) Background". The Library of
       Congress. 2019-10-08 [2019-03-01]. Archived from the original on
       2020-03-07. Retrieved 2020-03-07.
   10. ^
       Link: mw-deduplicated-inline-style
       "Extended Date/Time Format (EDTF) 1.0 2012/2014". Draft Submission.
       The Library of Congress. Archived from the original on 2017-07-15.
       Retrieved 2017-07-15.
   11. ^
       Link: mw-deduplicated-inline-style
       "ISO/WD 8601-2:2016-02-16" (PDF). Library of Congress. Archived from
       the original (PDF) on 2017-10-19.
   12. ^
       Link: mw-deduplicated-inline-style
       "ISO/DIS 8601-2:2016-10-26" (PDF). Library of Congress. Archived from
       the original (PDF) on 2017-10-20.
   13. ^
       Link: mw-deduplicated-inline-style
       "German draft E DIN ISO 8601-2:2017-02 Datenelemente und
       Austauschformate - Informationsaustausch - Darstellung von Datum und
       Uhrzeit - Teil 2: Erweiterungen (ISO/DIS 8601-2:2016)".
       DIN-Normenausschuss Informationstechnik und Anwendungen (NIA).
       Archived from the original on 2017-10-19. Retrieved 2017-10-19.
   14. ^ ^a ^b ISO, FAQ: Numeric representation of Dates and Time Archived
       2013-03-08 at the Wayback Machine
   15. ^
       Link: mw-deduplicated-inline-style
       "Date and Time Formats". w3.org. Archived from the original on 10 May
       2021. Retrieved 11 May 2021.
   16. ^ ISO 8601:2004 section 2.3.3 basic format
   17. ^ Earlier versions of ISO 8601 used the word accuracy, not precision,
       in the relevant section, e.g: 2.3.7 representation with reduced
       accuracy. This was corrected in ISO 8601-1:2019.
   18. ^
       Link: mw-deduplicated-inline-style
       Doggett, L. E. (1992). "Calendars". In P. K. Seidelmann (ed.).
       Explanatory Supplement to the Astronomical Almanac. Sausalito,
       California: University Science Books. p. 580. ISBN 0-935702-68-7.
       Archived from the original on 2004-04-01. The Gregorian calendar today
       serves as an international standard for civil use.
   19. ^
       Link: mw-deduplicated-inline-style
       ISO 8601:2004(E). ISO. 2004-12-01. section 4.1.2.1 General.
   20. ^
       Link: mw-deduplicated-inline-style
       ISO 8601:2004(E). ISO. 2004-12-01. 3.5 Expansion ... By mutual
       agreement of the partners in information interchange, it is permitted
       to expand the component identifying the calendar year, which is
       otherwise limited to four digits. This enables reference to dates and
       times in calendar years outside the range supported by complete
       representations, i.e. before the start of the year [0000] or after the
       end of the year [9999].
   21. ^ ISO 8601:2004 sections 3.4.2, 4.1.2.4
   22. ^ For example, see Annex B.1.1 of the standard.
   23. ^
       Link: mw-deduplicated-inline-style
       Perreault, Simon (August 2011). "RFC 6350 - vCard Format
       Specification". IETF. Archived from the original on 2016-05-31.
       Retrieved 2016-06-29. Truncated representation, as specified in
       [ISO.8601.2000], Sections 5.2.1.3 d), e), and f), is permitted. {{cite
       journal}}: Cite journal requires |journal= (help)
   24. ^ ISO 8601-1:2019 section 5.3.1.3 Representations with reduced
       precision
   25. ^ ISO 8601-1:2019 section 3.1.3.9 Decimal sign
   26. ^
       Link: mw-deduplicated-inline-style
       ISO 8601:2004(E), ISO, 2004-12-01, 4.2.2.4 ... the decimal fraction
       shall be divided from the integer part by the decimal sign specified
       in ISO 31-0, i.e. the comma [,] or full stop [.]. Of these, the comma
       is the preferred sign.
   27. ^
       Link: mw-deduplicated-inline-style
       "ISO 8601 Format". TechNet. Microsoft Docs. Archived from the original
       on 2021-10-20. Retrieved 2021-10-20.
   28. ^
       Link: mw-deduplicated-inline-style
       "COMMUNICATION INSTRUCTIONS GENERAL ACP 121(I)" (PDF). Combined
       Communications Electronics Board. October 2010. Archived (PDF) from
       the original on 2018-01-16. Retrieved 2018-01-15.
   29. ^
       Link: mw-deduplicated-inline-style
       McCarthy, Dennis D.; Seidelmann, Kenneth P. (2009). Time: From Earth
       Rotation to Atomic Physics. Weinheim: Wiley-VCH Verlag GmbH & Co.
       KGaA. p. 10. ISBN 978-3-527-40780-4.
   30. ^ ISO 8601-1:2019 section 3.2.4, ISO 8601:2004 section 3.4.2
   31. ^ RFC 3339 – Unknown local offset convention
   32. ^
       Link: mw-deduplicated-inline-style
       Newman, Chris (July 2002). Klyne, Graham (ed.). Date and Time on the
       Internet: Timestamps. IETF Tools Pages. Reston, VA: IETF Secretariat,
       Corp. for National Research Initiatives. p. 4. OCLC 43315042. Archived
       from the original on 20 January 2021. Retrieved 1 February 2021.
       Unknown Local Offset Convention: If the time in UTC is known, but the
       offset to local time is unknown, this can be represented with an
       offset of "-00:00". This differs semantically from an offset of "Z" or
       "+00:00", which imply that UTC is the preferred reference point for
       the specified time. RFC2822 [IMAIL-UPDATE] describes a similar
       convention for email
   33. ^
       Link: mw-deduplicated-inline-style
       "ISO 8601:2004(E)". ISO. 2004-12-01. 4.3.2 NOTE: By mutual agreement
       of the partners in information interchange, the character [T] may be
       omitted in applications where there is no risk of confusing a date and
       time of day representation with others defined in this International
       Standard. {{cite journal}}: Cite journal requires |journal= (help)
   34. ^
       Link: mw-deduplicated-inline-style
       "RFC 3339". 2002-07-01. 5.6. NOTE: ISO 8601 defines date and time
       separated by "T". Applications using this syntax may choose, for the
       sake of readability, to specify a full-date and full-time separated by
       (say) a space character. {{cite journal}}: Cite journal requires
       |journal= (help)
   35. ^
       Link: mw-deduplicated-inline-style
       "Data elements and interchange formats — Information interchange -
       Representation of dates and times — Part 1: Basic rules" (PDF). The
       Library of Congress. p. 23. Archived (PDF) from the original on
       2021-03-12. Retrieved 2021-07-06. b) If necessary for a particular
       application, the lowest order components may have a decimal fraction.
   36. ^ ISO 8601:2004 section 4.4.3.3 Alternative format, ISO 8601-1:2019
       section 5.5.2.4 Alternative format
   37. ^
       Link: mw-deduplicated-inline-style
       "Java 8 Class Duration". Java Platform Standard Edition 8. Oracle.
       Archived from the original on 2017-10-14. Retrieved 2017-10-07.
   38. ^
       Link: mw-deduplicated-inline-style
       "Amazon Alexa Duration". Amazon Developer. Amazon.com. Archived from
       the original on 2017-10-14. Retrieved 2017-10-07.
   39. ^
       Link: mw-deduplicated-inline-style
       "Info on ISO 8601, the date and time representation standard".
       Cs.tut.fi. Archived from the original on 2017-10-14. Retrieved
       2012-08-29.
   40. ^
       Link: mw-deduplicated-inline-style
       "ISO 8601 - Getting with the Times (and Dates)". Hydrogold.
       2012-01-01. Archived from the original on 2014-01-25. Retrieved
       2013-08-13.
   41. ^ Note about Date and Time Formats to W3C from Reuters Archived
       2011-08-23 at WebCite
   42. ^
       Link: mw-deduplicated-inline-style
       Nilsson, M. (2000-11-01). "ID3 tag version 2.4.0 - Main Structure".
       id3.org. pp. §4. Archived from the original on 2015-03-09. Retrieved
       2009-09-27.
   43. ^
       Link: mw-deduplicated-inline-style
       Newman, Chris; Klyne, Graham (July 2002). "RFC 3339". ietf.org.
       Archived from the original on 2015-10-20. Retrieved 2015-10-25.
   44. ^
       Link: mw-deduplicated-inline-style
       Newman, Chris; Klyne, Graham (July 2002). "RFC 3339, section 5.6".
       ietf.org. Archived from the original on 2015-10-20. Retrieved
       2015-10-25.
   45. ^ National Standard of Canada,
       Link: mw-deduplicated-inline-style
       "CAN/CSA-Z234.4-89 (R2007): All-Numeric Dates and Times". Standards
       Council of Canada. 31 December 1989. Archived from the original on 30
       March 2018. Retrieved 29 March 2018.
   46. ^
       Link: mw-deduplicated-inline-style
       "DOF - Diario Oficial de la Federación". Archived from the original on
       2021-11-10. Retrieved 2021-11-10.
   47. ^
       Link: mw-deduplicated-inline-style
       Czubla, Albin (2020-12-04). "Główny Urząd Miar" (PDF). Główny Urząd
       Miar. Archived (PDF) from the original on 2020-12-04. Retrieved
       2020-12-04.
   48. ^
       Link: mw-deduplicated-inline-style
       "SANS 8601:2009 (Ed. 2.00)". SABS Webstore. Archived from the original
       on 2021-11-24. Retrieved 2021-11-24.

External links[edit]

    Wikimedia Commons has media related to ISO 8601. 

     * ISO's catalog entry for ISO 8601:2004
     * The latest prototype of ISO 8601-1 (ISO/TC 154 N)
     * The latest prototype of ISO 8601-2 (ISO/TC 154 N)
     * Use international date format (ISO) – Quality Web Tips The World Wide
       Web Consortium (W3C)
     * ISO 8601 at Curlie
     * ISO 8601 summary by Markus Kuhn
     * Summary of 8601 by ISO at the Wayback Machine (archived 2011-06-14)
     * The Mathematics of the ISO 8601 Calendar
     * W3C Specification about UTC Date and Time, based on ISO 8601:1988
     * IETF
       Link: mw-deduplicated-inline-style
       Newman, Chris; Klyne, Graham (July 2002). "RFC 3339". {{cite
       journal}}: Cite journal requires |journal= (help) based on ISO
       8601:2000
     * RFC 3339 vs ISO 8601 — Venn diagram illustrating the difference
       between the two standards.
     * Link: mw-deduplicated-inline-style
       "ISO 8601-1:2019". Retrieved 2020-10-23.
     * Link: mw-deduplicated-inline-style
       "ISO 8601-2:2019". Retrieved 2020-10-23.

   Implementation overview

     * ISO 8601 Implementation Around The World

     * v               
     * t               
     * e               
   Time measurement and standards
     * Chronometry     
     * Orders of magnitude
     * Metrology       
                         * Coordinated Universal Time                         
                              * offset                                        
                         * UT                                    
                         * ΔT                                    
                         * DUT1                                  
                         * International Earth Rotation and      
                           Reference Systems Service             
                         * ISO 31-1                              
                         * ISO 8601                              
                         * International Atomic Time             
                         * 12-hour clock                         
   International         * 24-hour clock                         
   standards             * Barycentric Coordinate Time           
                         * Barycentric Dynamical Time            
                         * Civil time                            
                         * Daylight saving time                  
                         * Geocentric Coordinate Time            
                         * International Date Line               
                         * IERS Reference Meridian               
                         * Leap second                           
                         * Solar time                            
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   Obsolete standards    * Greenwich Mean Time                   
                         * Prime meridian                        
                         * Absolute space and time               
                         * Spacetime                             
                         * Chronon                               
                         * Continuous signal                     
                         * Coordinate time                       
                         * Cosmological decade                   
   Time in physics       * Discrete time and continuous time     
                         * Proper time                           
                         * Theory of relativity                  
                         * Time dilation                         
                         * Gravitational time dilation           
                         * Time domain                           
                         * Time translation symmetry             
                         * T-symmetry                            
                         * Clock                                 
                         * Astrarium                             
                         * Atomic clock                          
                         * Complication                          
                         * History of timekeeping devices        
                         * Hourglass                             
                         * Marine chronometer                    
                         * Marine sandglass                      
   Horology              * Radio clock                           
                         * Watch                                 
                              * stopwatch                        
                         * Water clock                           
                         * Sundial                               
                         * Dialing scales                        
                         * Equation of time                      
                         * History of sundials                   template
                         * Sundial markup schema                 illustration
                         * Gregorian                             
                         * Hebrew                                
                         * Hindu                                 
                         * Holocene                              
                         * Islamic (lunar Hijri)                 
                         * Julian                                
                         * Solar Hijri                           
                         * Astronomical                          
                         * Dominical letter                      
                         * Epact                                 
   Calendar              * Equinox                               
                         * Intercalation                         
                         * Julian date                           
                         * Leap year                             
                         * Lunar                                 
                         * Lunisolar                             
                         * Solar                                 
                         * Solstice                              
                         * Tropical year                         
                         * Weekday determination                 
                         * Weekday names                         
                         * Chronological dating                  
   Archaeology and       * Geologic time scale                   
   geology               * International Commission on           
                           Stratigraphy                          
                         * Galactic year                         
   Astronomical          * Nuclear timescale                     
   chronology            * Precession                            
                         * Sidereal time                         
                         * Flick                                 
                         * Shake                                 
                         * Jiffy                                 
                         * Second                                
                         * Minute                                
                         * Moment                                
                         * Hour                                  
                         * Day                                   
   Other units of time   * Week                                  
                         * Fortnight                             
                         * Month                                 
                         * Year                                  
                         * Olympiad                              
                         * Lustrum                               
                         * Decade                                
                         * Century                               
                         * Saeculum                              
                         * Millennium                            
                         * Chronology                            
                         * Duration                              
                              * music                            
                         * Mental chronometry                    
   Related topics        * Decimal time                          
                         * Metric time                           
                         * System time                           
                         * Time metrology                        
                         * Time value of money                   
                         * Timekeeper                            

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                                     * -1                    
                                     * -2                    
                                     * -3                    
                                * 3297                       
                                * 3307                       
                                * 3601                       
                                * 3602                       
                                * 3864                       
                                * 3901                       
                                * 3950                       
   1–9999                       * 3977                       
                                * 4031                       
                                * 4157                       
                                * 4165                       
                                * 4217                       
                                * 4909                       
                                * 5218                       
                                * 5426                       
                                * 5427                       
                                * 5428                       
                                * 5725                       
                                * 5775                       
                                * 5776                       
                                * 5800                       
                                * 5807                       
                                * 5964                       
                                * 6166                       
                                * 6344                       
                                * 6346                       
                                * 6385                       
                                * 6425                       
                                * 6429                       
                                * 6438                       
                                * 6523                       
                                * 6709                       
                                * 6943                       
                                * 7001                       
                                * 7002                       
                                * 7010                       
                                * 7027                       
                                * 7064                       
                                * 7098                       
                                * 7185                       
                                * 7200                       
                                * 7498                       
                                     * -1                    
                                * 7637                       
                                * 7736                       
                                * 7810                       
                                * 7811                       
                                * 7812                       
                                * 7813                       
                                * 7816                       
                                * 7942                       
                                * 8000                       
                                * 8093                       
                                * 8178                       
                                * 8217                       
                                * 8373                       
                                * 8501-1                     
                                * 8571                       
                                * 8583                       
                                * 8601                       
                                * 8613                       
                                * 8632                       
                                * 8651                       
                                * 8652                       
                                * 8691                       
                                * 8805/8806                  
                                * 8807                       
                                * 8820-5                     
                                * 8859                       
                                     * -1                    
                                     * -2                    
                                     * -3                    
                                     * -4                    
                                     * -5                    
                                     * -6                    
                                     * -7                    
                                     * -8                    
                                     * -8-I                  
                                     * -9                    
                                     * -10                   
                                     * -11                   
                                     * -12                   
                                     * -13                   
                                     * -14                   
                                     * -15                   
                                     * -16                   
                                * 8879                       
                                * 9000/9001                  
                                * 9036                       
                                * 9075                       
                                * 9126                       
                                * 9141                       
                                * 9227                       
                                * 9241                       
                                * 9293                       
                                * 9314                       
                                * 9362                       
                                * 9407                       
                                * 9496                       
                                * 9506                       
                                * 9529                       
                                * 9564                       
                                * 9592/9593                  
                                * 9594                       
                                * 9660                       
                                * 9797-1                     
                                * 9897                       
                                * 9899                       
                                * 9945                       
                                * 9984                       
                                * 9985                       
                                * 9995                       
                                * 10005                      
                                * 10006                      
                                * 10007                      
                                * 10116                      
                                * 10118-3                    
                                * 10160                      
                                * 10161                      
                                * 10165                      
                                * 10179                      
                                * 10206                      
                                * 10218                      
                                * 10303                      
                                     * -11                   
                                     * -21                   
                                     * -22                   
                                     * -28                   
                                     * -238                  
                                * 10383                      
                                * 10487                      
                                * 10585                      
                                * 10589                      
                                * 10628                      
                                * 10646                      
                                * 10664                      
                                * 10746                      
                                * 10861                      
                                * 10957                      
                                * 10962                      
                                * 10967                      
                                * 11073                      
                                * 11170                      
                                * 11179                      
                                * 11404                      
                                * 11544                      
                                * 11783                      
                                * 11784                      
                                * 11785                      
                                * 11801                      
                                * 11889                      
                                * 11898                      
                                * 11940 (-2)                 
                                * 11941                      
                                * 11941 (TR)                 
                                * 11992                      
                                * 12006                      
                                * 12182                      
                                * 12207                      
                                * 12234-2                    
                                * 12620                      
                                * 13211                      
                                     * -1                    
                                     * -2                    
                                * 13216                      
                                * 13250                      
                                * 13399                      
                                * 13406-2                    
                                * 13450                      
                                * 13485                      
                                * 13490                      
                                * 13567                      
                                * 13568                      
                                * 13584                      
                                * 13616                      
                                * 13816                      
                                * 14000                      
                                * 14031                      
                                * 14224                      
                                * 14289                      
                                * 14396                      
                                * 14443                      
                                * 14496                      
                                     * -2                    
                                     * -3                    
                                     * -6                    
                                     * -10                   
                                     * -11                   
                                     * -12                   
                                     * -14                   
                                     * -17                   
   10000–19999                       * -20                   
                                * 14617                      
                                * 14644                      
                                * 14649                      
                                * 14651                      
                                * 14698                      
                                * 14764                      
                                * 14882                      
                                * 14971                      
                                * 15022                      
                                * 15189                      
                                * 15288                      
                                * 15291                      
                                * 15292                      
                                * 15398                      
                                * 15408                      
                                * 15444                      
                                     * -3                    
                                * 15445                      
                                * 15438                      
                                * 15504                      
                                * 15511                      
                                * 15686                      
                                * 15693                      
                                * 15706                      
                                     * -2                    
                                * 15707                      
                                * 15897                      
                                * 15919                      
                                * 15924                      
                                * 15926                      
                                * 15926 WIP                  
                                * 15930                      
                                * 16023                      
                                * 16262                      
                                * 16355-1                    
                                * 16612-2                    
                                * 16750                      
                                * 16949 (TS)                 
                                * 17024                      
                                * 17025                      
                                * 17100                      
                                * 17203                      
                                * 17369                      
                                * 17442                      
                                * 17506                      
                                * 17799                      
                                * 18000                      
                                * 18004                      
                                * 18014                      
                                * 18245                      
                                * 18629                      
                                * 18916                      
                                * 19005                      
                                * 19011                      
                                * 19092                      
                                     * -1                    
                                     * -2                    
                                * 19114                      
                                * 19115                      
                                * 19125                      
                                * 19136                      
                                * 19407                      
                                * 19439                      
                                * 19500                      
                                * 19501                      
                                * 19502                      
                                * 19503                      
                                * 19505                      
                                * 19506                      
                                * 19507                      
                                * 19508                      
                                * 19509                      
                                * 19510                      
                                * 19600                      
                                * 19752                      
                                * 19757                      
                                * 19770                      
                                * 19775-1                    
                                * 19794-5                    
                                * 19831                      
                                * 20000                      
                                * 20022                      
                                * 20121                      
                                * 20400                      
                                * 20802                      
                                * 21000                      
                                * 21047                      
                                * 21500                      
                                * 21827                      
                                * 22000                      
                                * 22300                      
                                * 22395                      
                                * 23090-3                    
                                * 23270                      
                                * 23271                      
                                * 23360                      
                                * 24517                      
                                * 24613                      
   20000–29999                  * 24617                      
                                * 24707                      
                                * 25178                      
                                * 25964                      
                                * 26000                      
                                * 26262                      
                                * 26300                      
                                * 26324                      
                                * 27000 series               
                                * 27000                      
                                * 27001                      
                                * 27002                      
                                * 27005                      
                                * 27006                      
                                * 27729                      
                                * 28000                      
                                * 29110                      
                                * 29148                      
                                * 29199-2                    
                                * 29500                      
                                * 30170                      
                                * 31000                      
                                * 32000                      
                                * 37001                      
                                * 38500                      
   30000+                       * 40500                      
                                * 42010                      
                                * 45001                      
                                * 50001                      
                                * 55000                      
                                * 56000                      
                                * 80000                      
     * Category               

   Retrieved from
   "https://en.wikipedia.org/w/index.php?title=ISO_8601&oldid=1081284249"
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     * Date and time representation
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