How to setting config.timezone in non-Rails application?

Hello all, I’m developing a sinatra application and loads ActiveRecord in,

the main server is in rails, the many clients is written in Sinatra, now
need to sync
job from server to client where saving the related datetime seems a
it seems rails has done some handling about timezone, when converting to
yaml to send,
it just “2012-08-29 16:00:00.000000000Z” (seems to convert to UTC and
have a Z in it
to denote it), and then in client, I need to de_yaml it, and saves it,
seems messy,
and do client has a way to set a TimeZone?
it seems in ThreadLocal fits this description, but do anybody
know how the param
pattern looks like?