calculate the number of months difference between two dates

Please share if there any such easy methods in rails. I have dates like

date1 =
date2 = - 3.months (Example can be anything)

     Now how to get month difference as 3 (date1 - date2)

Thanks for any help

Googling for "ruby months between two dates" gleans this as the first result:

...and loads of other likely candidates.