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lib/Date/Holidays/TW.pm  view on Meta::CPAN

sub __is_tw_lunar_holiday {
    my ($dt) = @_;
    my $lunar_date = DateTime::Calendar::Chinese->from_object(object => $dt);
    return undef if $lunar_date->leap_month;
    my $lunar_mmdd = sprintf('%02d%02d', $lunar_date->month, $lunar_date->day);
    return $FOLK_LUNAR{$lunar_mmdd};
}

sub __is_qingming {
    # Thanks Wei-Hon Chen for the formula.
    my $dt = $_[0];
    return undef unless $dt->month == 4 && 3 < $dt->day && $dt->day < 6;
    my $year = $dt->year;
    die "Unsupported" if $year < 1901 || 2100 < $year;
    my $Y = ($year % 100);
    my $C = (1901 <= $year && $year < 2001) ? 5.59 : 4.81;
    my $n = int($Y * 0.2422 + 4.81) - int($Y / 4);
    return $dt->day == $n ? '民族掃墓節' : undef;
}