Query client's timezone with Google AppEngine XMPP library

Context

I have a jabber bot implemented in Python on Google AppEngine and their xmpp library. The bot forwards posts from a social network and I'd like post time开发者_开发知识库stamps are in client's timezone.

Question

Is it possible (and how) to query client for their local timezone so my bot can do respective adjustments? Again, the bot is based on appengine's xmpp python library.

Alternatives

Of course, it can ask clients to specify their timezone explicitly on setup, store that value somewhere and use it later. But I'd prefer my bot extracts this information automatically, without human involvement.

Respective documentation

http://code.google.com/appengine/docs/python/xmpp/

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Currently it is not possible, although XMPP has the ability to query for time zone Google App Engine doesn't allow to send raw stanzas.
There is an issue about it in acknowledged mode but don't bet on seeing it anytime soon.