Ruby Months Between

#!/usr/bin/ruby 

require 'date'

class Date

  def self.months_between(d1, d2)
    months = []
    start_date = Date.civil(d1.year, d1.month, 1)
    end_date = Date.civil(d2.year, d2.month, 1)

    raise ArgumentError unless d1 <= d2

    while (start_date < end_date)
      months << start_date
      start_date = start_date >>1
    end

    months << end_date

  end
end


# Date.months_between '2012-09-01'.to_date, Date.today.to_date