[tz] Re: Use -00 only for invalid time zones

Thanks for reporting that. I installed the attached; the first is your patch with very minor changes; the second documents the change. I didn't know this this code was used in freebsd-src/contrib/tzcode. I now see that there are some minor differences between the FreeBSD copy; would it make sense to merge these into tzcode, perhaps with some "#ifdef __FreeBSD__"s thrown in? I suspect that would save time overall in the long run.