How to get Rails to interpret a time as being in a specific time zone?

Question

In Ruby 1.8.7, how to set the time zone of a time?

In the following examples, my system time zone is PST (-8:00 hours from UTC)

Given a time (21 Feb 2011

Answer 1

In ruby 1.8.7 it doesn't appear to be very easy to do what are asking for according to the documentation:

http://www.ruby-doc.org/core-1.8.7/classes/Time.html

However in 1.9 it looks a lot easier by passing the timezone offset to the localtime() method on a Time object:

http://www.ruby-doc.org/core/classes/Time.html#M000346

UPDATE

The offset for Time.zone is easy since its an object on its own: (This is in a Rails console)

ruby-1.8.7-p248 :001 > Time.zone
 => #, @utc_offset=nil> 
ruby-1.8.7-p248 :002 > Time.zone.utc_offset
 => -21600 
ruby-1.8.7-p248 :003 > Time.zone.formatted_offset
 => "-06:00"