I work for a company that requires some capabilities beyond the standard time zone library. Here's the sort of thing we're interested in: Ability to efficiently do time calculations in several time zones at the same time in separate threads. Time zone functions might take a zone as argument instead of the current method of setting the TZ environment variable and calling tzset to change zones, which involves file I/O. Is there any prior art along these lines? I do see the routines whose names end with "_r". They seem to fix one glitch, but do not completely solve the problem. How can I get the capabilities I want integrated with the standard time zone library? By making it a part of the standard library, the chance increases that the code will be used, maintained, and completely debugged. We are willing to pay for the capabilities we want. Would Cygnus be a good source for this work? Do you have any other suggestions? Thanks very much. bob