NAME
    App::datecalc - Date calculator

VERSION
    This document describes version 0.08 of App::datecalc (from Perl
    distribution App-datecalc), released on 2018-02-21.

SYNOPSIS
     use App::datecalc;
     my $calc = App::datecalc->new;
     say $calc->eval('2014-05-13 + 2 days'); # -> 2014-05-15

DESCRIPTION
    This is an early release. More features and documentation will follow in
    subsequent releases.

    This module provides a date calculator, for doing date-related
    calculations. You can write date literals in ISO 8601 format (though not
    all format variants are supported), e.g. "2014-05-13". Date duration can
    be specified using the natural syntax e.g. "2 days 13 hours" or using
    the ISO 8601 format e.g. "P2DT13H".

    Currently supported calculations:

    *   date literals

         2014-05-19
         now
         today
         tomorrow

    *   (NOT YET) time and date-time literals

    *   duration literals, either in ISO 8601 format or natural syntax

         P3M2D
         3 months 2 days

    *   date addition/subtraction with a duration

         2014-05-19 - 2 days
         2014-05-19 + P29W

    *   date subtraction with another date

         2014-05-19 - 2013-12-25

    *   duration addition/subtraction with another duration

         1 week 1 day + P10D

    *   duration multiplication/division with a number

         P2D * 2
         2 * P2D

    *   extract elements from date

         year(2014-05-20)
         quarter(today)
         month(today)
         day(today)
         dow(today)
         doy(today)
         doq(today)
         wom(today)
         woy(today)
         hour(today)
         minute(today)
         second(today)

    *   extract elements from duration

         years(P22D)
         months(P22D)
         weeks(P22D)
         days(P22D)       # 1, because P22D normalizes to P3W1D
         totdays(P22D)    # 22
         days(P1M1D)      # 1
         totdays(P1M1D)   # 1, because months cannot be converted to days
         hours(P22D)
         minutes(P22D)
         seconds(P22D)

    *   some simple number arithmetics

         3+4.5
         2**3 * P1D
         abs(2-5)         # 3
         round(1.6+3)     # 5

    *   (NOT YET) date comparison

         today >= 2014-05-20

    *   (NOT YET) duration comparison

         P20D < P3W

METHODS
  new
  eval
HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/App-datecalc>.

SOURCE
    Source repository is at
    <https://github.com/perlancar/perl-App-datecalc>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=App-datecalc>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

SEE ALSO
    DateTime and DateTime::Format::ISO8601, the backend modules used to do
    the actual date calculation.

    Marpa::R2 is used to generate the parser.

    Date::Calc another date module on CPAN. No relation except the
    similarity of name.

    <http://en.wikipedia.org/wiki/ISO_8601> for more information about the
    ISO 8601 format.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2018, 2016, 2015, 2014 by
    perlancar@cpan.org.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.