# File lib/holidays/jp.rb, line 53 def self.jp_vernal_equinox_day(year) day = case year when 1851..1899 19.8277 when 1900..1979 20.8357 when 1980..2099 20.8431 when 2100..2150 21.8510 else raise IndexError.new("Out of range") end day += 0.242194 * (year - 1980) - ((year - 1980)/4).floor day = day.floor Date.civil(year, 3, day) end