def month_choices(month_names = settings.default_month_names)
      month_names.map.
        with_index { |month, idx| [month, idx] }.
        tap        { |arr| arr.shift }
    end
def month_choices(month_names = settings.default_month_names)
      month_names.map.
        with_index { |month, idx| [month, idx] }.
        tap        { |arr| arr.shift }
    end
Returns an array of pairs i.e.
 - ['January', 1]
 - ['February', 2]
 - ...
 - ['December', 12]

 You may pass in Date::ABBR_MONTHNAMES if you want the shortened month names.

 @param  [Array] month_names (defaults to Date::MONTHNAMES) an array with the
                 first element being nil, element 1 being January, etc.
 @return [Array] the array of month name, month pairs.