# phpman > man > DateTime::Format::ISO8601(3pm) ## NAME [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown) - Parses ISO8601 formats ## VERSION version 0.16 ## SYNOPSIS use [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown); my $datetime_str = '2020-07-25T11:32:31'; my $dt = [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->parse_datetime($datetime_str); say $dt; # This format is ambiguous and could be either a date or time, so use the # parse_time method. my $time_str = '113231'; $dt = [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->parse_time($time_str); say $dt; # or my $iso8601 = [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->new; $dt = $iso8601->parse_datetime($datetime_str); say $dt; $dt = $iso8601->parse_time($time_str); say $dt; say [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->format_datetime($dt); ## DESCRIPTION Parses almost all ISO8601 date and time formats. ISO8601 time-intervals will be supported in a later release. ## METHODS This class provides the following methods: ### Constructors [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->new( ... ) Accepts an optional hash. my $iso8601 = [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->new( base_datetime => $dt, cut_off_year => 42, legacy_year => 1, ); * base_datetime A "DateTime" object that will be used to fill in missing information from incomplete date/time formats. This key is optional. * cut_off_year A integer representing the cut-off point between interpreting 2-digits years as 19xx or 20xx. 2-digit years < cut_off_year will be interpreted as 20xx 2-digit years >= cut_off_year will be untreated as 19xx This key defaults to the value of "DefaultCutOffYear". * legacy_year A boolean value controlling if a 2-digit year is interpreted as being in the current century (unless a "base_datetime" is set) or if "cut_off_year" should be used to place the year in either 20xx or 19xx. If this is true, then the "cut_off_year" is used. If this is false, then the year is always interpreted as being in the current century. This key defaults to the value of "DefaultLegacyYear". $iso8601->clone Returns a replica of the given object. ### Object Methods $iso8601->base_datetime Returns a "DateTime" object if a "base_datetime" has been set. $iso8601->set_base_datetime( object => $object ) Accepts a "DateTime" object that will be used to fill in missing information from incomplete date/time formats. $iso8601->cut_off_year Returns a integer representing the cut-off point between interpreting 2-digits years as 19xx or 20xx. $iso8601->set_cut_off_year($int) Accepts a integer representing the cut-off point between interpreting 2-digits years as 19xx or 20xx. 2-digit years < legacy_year will be interpreted as 20xx 2-digit years >= legacy_year will be interpreted as 19xx $iso8601->legacy_year Returns a boolean value indicating the 2-digit year handling behavior. $iso8601->set_legacy_year($bool) Accepts a boolean value controlling if a 2-digit year is interpreted as being in the current century (unless a "base_datetime" is set) or if "cut_off_year" should be used to place the year in either 20xx or 19xx. ### Class Methods [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->DefaultCutOffYear($int) Accepts a integer representing the cut-off point for 2-digit years when calling "parse_*" as class methods and the default value for "cut_off_year" when creating objects. If called with no parameters this method will return the default value for "cut_off_year". [DateTime::Format::ISO8601](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3AISO8601/markdown)->DefaultLegacyYear($bool) Accepts a boolean value controlling the legacy year behavior when calling "parse_*" as class methods and the default value for "legacy_year" when creating objects. If called with no parameters this method will return the default value for "legacy_year". Parser(s) These methods may be called as either class or object methods. parse_datetime parse_time Please see the "FORMATS" section. ### Formatter This may be called as either class or object method. format_datetime($dt) Formats the datetime in an ISO8601-compatible format. This differs from "iso8601" in DateTime by including nanoseconds/milliseconds and the correct timezone offset. ## FORMATS There are 6 strings that can match against date only or time only formats. The "parse_datetime" method will attempt to match these ambiguous strings against date only formats. If you want to match against the time only formats use the "parse_time" method. ### Conventions * Expanded ISO8601 These formats are supported with exactly 6 digits for the year. Support for a variable number of digits will be in a later release. * Precision If a format doesn't include a year all larger time unit up to and including the year are filled in using the current date/time or [if set] the "base_datetime" object. * Fractional time There is no limit on the expressed precision. ### Supported via parsedatetime The supported formats are listed by the section of ISO 8601:2000(E) in which they appear. 5.2 Dates * 5.2.1.1 YYYYMMDD YYYY-MM-DD * 5.2.1.2 YYYY-MM YYYY YY * 5.2.1.3 YYMMDD YY-MM-DD ### -YYMM ### -YY-MM ### -YY ### --MMDD ### --MM-DD ### --MM ---DD * 5.2.1.4 +[YY]YYYYMMDD +[YY]YYYY-MM-DD +[YY]YYYY-MM +[YY]YYYY +[YY]YY * 5.2.2.1 YYYYDDD YYYY-DDD * 5.2.2.2 YYDDD YY-DDD ### -DDD * 5.2.2.3 +[YY]YYYYDDD +[YY]YYYY-DDD * 5.2.3.1 YYYYWwwD YYYY-Www-D * 5.2.3.2 YYYYWww YYYY-Www YYWwwD YY-Www-D YYWww YY-Www ### -YWwwD ### -Y-Www-D ### -YWww ### -Y-Www ### -WwwD ### -Www-D ### -Www ### -W-D * 5.2.3.4 +[YY]YYYYWwwD +[YY]YYYY-Www-D +[YY]YYYYWww +[YY]YYYY-Www 5.3 Time of Day * 5.3.1.1 - 5.3.1.3 Values can optionally be prefixed with 'T'. * 5.3.1.1 hh:mm:ss * 5.3.1.2 hh:mm * 5.3.1.3 - 5.3.1.4 fractional (decimal) separator maybe either ',' or '.' * 5.3.1.3 hhmmss,ss hh:mm:ss,ss hhmm,mm hh:mm,mm hh,hh * 5.3.1.4 -mm:ss -mmss,s -mm:ss,s -mm,m --ss,s * 5.3.3 - 5.3.4.2 Values can optionally be prefixed with 'T'. * 5.3.3 hhmmssZ hh:mm:ssZ hhmmZ hh:mmZ hhZ hhmmss.ssZ hh:mm:ss.ssZ * 5.3.4.2 hhmmss[+-]hhmm hh:mm:ss[+-]hh:mm hhmmss[+-]hh hh:mm:ss[+-]hh hhmmss.ss[+-]hhmm hh:mm:ss.ss[+-]hh:mm 5.4 Combinations of date and time of day * 5.4.1 YYYYMMDDThhmmss YYYY-MM-DDThh:mm:ss YYYYMMDDThhmmssZ YYYY-MM-DDThh:mm:ssZ YYYYMMDDThhmmss[+-]hhmm YYYY-MM-DDThh:mm:ss[+-]hh:mm YYYYMMDDThhmmss[+-]hh YYYY-MM-DDThh:mm:ss[+-]hh * 5.4.2 YYYYMMDDThhmmss.ss YYYY-MM-DDThh:mm:ss.ss YYYYMMDDThhmmss.ss[+-]hh YYYY-MM-DDThh:mm:ss.ss[+-]hh YYYYMMDDThhmmss.ss[+-]hhmm YYYY-MM-DDThh:mm:ss.ss[+-]hh:mm * 5.4.3 Support for this section is not complete. YYYYMMDDThhmm YYYY-MM-DDThh:mm YYYYMMDDThhmmZ YYYY-MM-DDThh:mmZ YYYYDDDThhmm YYYY-DDDThh:mm YYYYDDDThhmmZ YYYY-DDDThh:mmZ YYYYWwwDThhmm[+-]hhmm YYYY-Www-DThh:mm[+-]hh 5.5 Time-Intervals These are not currently supported ### Supported via parsetime 5.3.1.1 - 5.3.1.3 Values can optionally be prefixed with 'T'. * 5.3.1.1 hhmmss * 5.3.1.2 hhmm hh * 5.3.1.4 ### -mmss ### -mm ### --ss ## STANDARDS DOCUMENT ### Title ISO8601:2000(E) Data elements and interchange formats - information exchange - Representation of dates and times Second edition 2000-12-15 ### Reference Number ISO/TC 154 N 362 ## CREDITS Iain 'Spoon' Truskett (SPOON) who wrote [DateTime::Format::Builder](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3ABuilder/markdown). That has grown into *The Vacuum Energy Powered "Swiss Army" Katana* of date and time parsing. This module was inspired by and conceived in honor of Iain's work. Tom Phoenix (PHOENIX) and PDX.pm for helping me solve the ISO week conversion bug. Not by fixing the code but motivation me to fix it so I could participate in a game of "Zendo". Jonathan Leffler (JOHNL) for reporting a test bug. Kelly McCauley for a patch to add 8 missing formats. Alasdair Allan (AALLAN) for complaining about excessive test execution time. Everyone at the DateTime "Asylum". ## SEE ALSO * DateTime * [DateTime::Format::Builder](https://www.chedong.com/phpMan.php/perldoc/DateTime%3A%3AFormat%3A%3ABuilder/markdown) ## SUPPORT Bugs may be submitted at <>. I am also usually active on IRC as 'autarch' on "irc://irc.perl.org". ## SOURCE The source code repository for DateTime-Format-ISO8601 can be found at <>. ## AUTHORS * Joshua Hoblitt <> * Dave Rolsky <> ## CONTRIBUTORS * Doug Bell <> * joe <> * Liam Widdowson <> * Thomas Klausner <> ## COPYRIGHT AND LICENSE This software is copyright (c) 2021 by Joshua Hoblitt. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. The full text of the license can be found in the LICENSE file included with this distribution.