# File lib/holidays/jp.rb, line 73
def self.jp_national_culture_day(year)
  day =
    case year
    when 1851..1899
      22.2588
    when 1900..1979
      23.2588
    when 1980..2099
      23.2488
    when 2100..2150
      24.2488
    else
      raise IndexError.new("Out of range")
    end
  day += 0.242194 * (year - 1980) - ((year - 1980)/4).floor
  day = day.floor
  Date.civil(year, 9, day)
end