Dear all,

One of the ways to configure Linux local time zone is via TZ environmental variable. Or, /etc/timezone.

It utilizes Posix TZ string:
EST5EDT,M03.2.0,M11.1.0 (Eastern time)

My questions are:
1. Is the posix TZ string able to (somehow) reflect which year the configuration is for?
2. If the answer of the question above is negative, will the time zone configuration, let's say EST5EDT,M03.2.0,M11.1.0, directly apply to whichever year the system time currently points to?

Thanks!
hellolqs

Nope.

Bear in mind that daylight saving time is political, not physical. When The Powers That Be decide to change the onset and..., uh, offset days, system libraries need to be changed to reflect that (as happened in the USA a few years ago). If the local time does not change (some US states do not), that must be reflected in the setting string but there isn't any consideration of the year.
Yep.

Actually, on a properly configured system you do not need to define TZ. You define the time zone the system lives in and that's that. You might set TZ if you are using a computer over a network from a different time zone, and would like times reported to you in the time zone local to you, rather than what is local to the computer. Too, you don't really need the extra arguments -- you can simply set TZ=EST5EDT and daylight on and off will be correct.

Hope this helps some.

Thank you! Got it.