Ruby Date Subtraction (e.g. 90 days Ago)

require 'date'
now = Date.today
ninety_days_ago = (now - 90)

Running this thru the IRB console I get:

>>require 'date'
now = Date.today
ninety_days_ago = (now - 90)

require 'date'
=> false
now = Date.today
=> #<Date: 2011-03-02 (4911245/2,0,2299161)>
ninety_days_ago = (now - 90)
=> #<Date: 2010-12-02 (4911065/2,0,2299161)>

If you need the time you could just say now = DateTime.now