On 5/10/21 11:04 AM, Paul Eggert wrote:
theory.html says that tzdb records civil time by "partitioning the world into timezones whose clocks all agree about timestamps that occur after the POSIX Epoch". Although it's true that the existence of such a partition doesn't logically require that each Zone history be distinct after the Epoch, that is the intent nowadays. I suppose this should be stated more clearly
On further thought, this point should be covered adequately later in theory.html, where it says "If all the clocks in a timezone have agreed since 1970, do not bother to include more than one timezone even if some of the clocks disagreed before 1970." However, I did notice that the wording said all tzdb timezone names are location-based, which isn't true for timezones like Etc/GMT-10. I installed the attached to try to fix this.