title: How can I set the time zone before calling strftime?
body: <p>I represent dates using seconds (and microseconds) since 1970 as well as a time zone and dst flag.  I want to print a representation of the date using strftime, but it uses the global value for timezone (extern long int timezone) that is picked up from the environment.  How can I get strftime to print the zone of my choice?</p>