t = Time.now
# => 2010-12-20 11:20:31 -0700
# Seconds since epoch
t.to_i
#=> 1292869231
require 'date'
d = Date.today
#=> #
epoch = Date.new(1970,1,1)
#=> #
d - epoch
#=> (14963/1)
# Days since epoch
(d - epoch).to_i
#=> 14963
# Seconds since epoch
d.to_time.to_i
#=> 1292828400