I'll hold off on changing backward and systemv in the upcoming Monday distribution; it's important to get other changes out at that point since some of them effect current clocks. The best approach to take on the systemv stuff may be to simply eliminate it from the distribution. The systemv stuff was included way back in 1986 when System V was still relevant; twenty years later it can presumably be dispensed with. On the backward side: a characteristic of the time zone compiler is that it doesn't clear out the destination directory before putting results there, so existing files remain unless they're replaced. Further, if a binary file exists with a name that matches that of the TZ environment variable, the data in the binary file is used even if the TZ value is something such as "EST5EDT". So we do want to generate binary files for EST5EDT et al. to ensure that no bad data remains in the destination directory. To avoid having US rules in both "northamerica" and "backward" (introducing the possibility that the rules get out of sync), we could put the "Zone EST5EDT ..." stuff in the northamerica file (where the US rules currently appear). If we do end up with two copies of the US rules, we'll want to make sure that there's a comment with each copy indicating the need to keep it in sync with the other copy. --ado