NAME

DateTime::Event::Chinese - DateTime Extension for Calculating Important Chinese Dates

SYNOPSIS

  use DateTime::Event::Chinese qw(:all);
  my $new_moon = chinese_new_years();

  my $dt0  = DateTime->new(...);
  my $next_new_year = $new_year->next($dt0);
  my $prev_new_year = $new_year->previous($dt0);

  my $dt1  = DateTime->new(...);
  my $dt2  = DateTime->new(...);
  my $span = DateTime::Span->new(start => $dt1, end => $dt2);

  my $set  = $new_year->intersection($span);
  my $iter = $set->iterator();

  while (my $dt = $iter->next) {
    print $dt->datetime, "\n";
  }

  my $new_year = chinese_new_year_for_sui($dt);
  my $new_year = chinese_new_year_for_gregorian_year($dt);
  my $new_year = chinese_new_year_after($dt);
  my $new_year = chinese_new_year_before($dt);

DESCRIPTION

This modules implements the algorithm described in "Calendrical Calculations" to compute some important Chinese dates, such as date of new year and other holidays (Currently only new years can be calculated).

FUNCTIONS

$set = chinese_new_years();

Returns a DateTime::Set that generates Chinese new years.

chinese_new_year_for_sui($dt)

Returns the DateTime object representing the Chinese New Year for the "sui" (the period between two winter solstices) of the given date.

  my $dt = chinese_new_year_for_sui($dt0);

chinese_new_year_for_greogrian_year($dt)

Returns the DateTime object representing the Chinese New Year for the given gregorian year.

  my $dt = chinese_new_year_for_sui($dt0);

chinese_new_year_after($dt)

Returns a DateTime object representing the next Chinese New Year relative to the given datetime argument.

  my $next_new_year = chinese_new_year_after($dt0);

This is the function that is internally used by new_year()->next().

chinese_new_year_before($dt)

Returns a DateTime object representing the previous Chinese New Year relative to the given datetime argument.

  my $prev_new_year = chinese_new_year_beore($dt0);

This is the function that is internally used by new_year()->previous().

AUTHOR

Daisuke Maki "<daisuke@endeworks.jp>"

LICENSE

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

See http://www.perl.com/perl/misc/Artistic.html

REFERENCES

  [1] Edward M. Reingold, Nachum Dershowitz
      "Calendrical Calculations (Millenium Edition)", 2nd ed.
       Cambridge University Press, Cambridge, UK 2002