This is how activerecord works:
Time.zone = 'Athens'
Post.first.created_at # => Thu, 27 May 2010 19:28:01 EEST +03:00
Time.zone = 'London'
Post.first.created_at # => Thu, 27 May 2010 17:28:01 BST +01:00
Datamapper ignores timezone. So to achieve the same effect you need to use in_time_zone method on time fields, which isn't very handy.
Created by kgiszczak - 2010-05-27 17:37:20 UTC
Original Lighthouse ticket: http://datamapper.lighthouseapp.com/projects/20609/tickets/1292
This ticket is related to #868
by Dan Kubb (dkubb)
@solnic I can take a look at this.