module Hiccup module CoreExtensions module Date def get_months_since(earlier_date) ((self.year - earlier_date.year) * 12) + (self.month - earlier_date.month).to_int end def get_years_since(earlier_date) (self.year - earlier_date.year) end def get_months_until(later_date) later_date.months_since(self) end def get_years_until(later_date) later_date.years_since(self) end end end end Date.send :include, Hiccup::CoreExtensions::Date DateTime.send :include, Hiccup::CoreExtensions::Date