use Perl

Locale::Country lists 240 countries. Out of these 240, 8 countries are present in the Date::Holidays::* namespace.

In order to make this namespace more usable, we need a better coverage - we need to go global :)

Currently the following countries are represented:

Norway, Denmark, Australia, New Zealand, Portugal, Germany, Great Britain/United Kingdom and France and USA is actually in preparation.

But plenty of countries are not represented.

I have just uploaded Date-Holidays_0.06 to CPAN, this module, contains documentation on how to comply with the other modules in the namespace.

From Date::Holidays_0.06 (slightly modified):

DEVELOPING A DATE::HOLIDAYS::* MODULE
        There is no control of the Date::Holidays::* namespace at all, so I am
        by no means an authority, but this is recommendations on order to make
        the modules in the Date::Holidays more uniform and thereby more usable.

        If you want to participate in the effort to make the Date::Holidays::*
        namespace even more usable, feel free to do so, your feedback and
        suggestions will be more than welcome.

        If you want to add your country to the Date::Holidays::* namespace,
        please feel free to do so. If a module for you country is already
        present, I am sure the author would not mind patches, suggestion or even
        help.

        If however you country does not seem to be represented in the namespace,
        you are more than welcome to become the author of the module in
        question.

        Please note that the country code is expected to be a two letter code
        based on ISO3166 (or Locale::Country).

        As an experiment I have added two modules to the namespace,
        Date::Holidays::Abstract and Date::Holidays::Super, abstract is attempt
        to make sure that the module implements the expected methods.

        So by using abstract your module will not work until it follows the the
        abstract layed out for a Date::Holidays::* module. Unfortunately the
        module will only check for the presence of the methods not their
        prototypes.

        Date::Holidays::Super is for the lazy programmer, it implements the
        necessary methods as stubs and there for do not have to implement
        anything, but your module will not return anything of value. So the
        methods need to be overwritten in order to comply with the expected
        output of a Date::Holidays::* method.

        The methods which are currently interesting in a Date::Holidays::*
        module are:

        is_holiday
                Takes 3 arguments: year, month, day and returns the name of the
                holiday as a scalar in the national language of the module context
                in question. Returns undef if the requested day is not a holiday.

                                Modified example taken from: Date::Holidays::DK

                                use Date::Holidays::DK;
                        my ($year, $month, $day) = (localtime)[ 5, 4, 3 ];

                                $year += 1900;
                        $month += 1;
                        print "Woohoo" if is_holiday( $year, $month, $day );

                                #The actual method might not be implemented at this time in the
                                #example module.

        is__holiday
                Same as above.

                This method however should be a wrapper of the above method (or the
                other way around).

        holidays
                Takes 1 argument: year and returns a hashref containing all of the
                holidays in specied for the country, in the national language of the
                module context in question.

                The keys are the dates, month + day in two digits each contatenated.

                                Modified example taken from: Date::Holidays::PT

                                my $h = holidays($year);
                                printf "Jan. 1st is named '%s'\n", $h->{'0101'};

                                #The actual method might not be implemented at this time in the
                                #example module.

        _holidays
                This method however should be a wrapper of the above method (or the
                other way around).

        Only is_holiday and holidays are implemented in Date::Holidays::Super
        and are required by Date::Holidays::Abstract.

    ADDITIONAL PARAMETERS
        Some countries are divided into regions or similar and might require
        additional parameters in order to give more exact holiday data.

        This is handled by adding additional parameters to is_holiday and
        holidays.

        These parameters are left to the module authors descretion and the
        actual Date::Holidays::* module should be consulted.

                        Example Date::Holidays::AU

                use Date::Holidays::AU qw( is_holiday );

                        my ($year, $month, $day) = (localtime)[ 5, 4, 3 ];
                $year += 1900;
                $month += 1;

                        my ($state) = 'VIC';
                print "Excellent\n" if is_holiday( $year, $month, $day, $state );