I was recently asked about how date/time stamps are stored in the TFS.  The concern was centered around distributed development that crosses timezones.  If someone in the UK checks in a piece of code to a server in California, how will the stamp be preserved so that a California user knows precisely when the code was modified?

Well, timestamps are stored in UTC (GMT).  The client (VS or command line, or whatever) converts the UTC time to local time for display.  This allows centrally-stored timestamps to be displayed in a manner most consistent with the requesting client's locale.