puts Time.local(2006, 1, 1) # => Sun Jan 01 00:00:00 EST 2006
puts Time.local(2006, 1, 1).isdst # => false
puts Time.local(2006, 10, 1) # => Sun Oct 01 00:00:00 EDT 2006
puts Time.local(2006, 10, 1).isdst # => true