On Tue, Aug 13, 2019 at 10:30:34AM -0700, Linus Torvalds wrote: > > I suspect the only actual _valid_ use in the kernel for a time zone > setting is likely for RTC clock setting, but even that isn't really > "global", as much as "per RTC".
As I recall (and I may or may not have been original for the original sys_tz; it was many years ago, and my memories of 1992 are a bit fuzzy) the only reason why we added it was because x86 systems that were dual-booting with Windows had a RTC which ticked localtime, and originally, the system time was fetched from the RTC in early boot, and then when the timezone was set, the time would be warped so it would be correct. Trying to use this for anything else is probably a bad idea, and in a world where we can have initrd's and reading the RTC gets done by userspace as opposed to kernel, it probably doesn't make any sence to keep it. Cheers, - Ted