/* Rectify the value of the environment variable TZ.
There are four possible kinds of such values:
- Traditional US time zone names, e.g. "PST8PDT". Syntax: see
- <https://msdn.microsoft.com/en-us/library/90s5c885.aspx>
+ <https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/tzset>
- Time zone names based on geography, that contain one or more
slashes, e.g. "Europe/Moscow".
- Time zone names based on geography, without slashes, e.g.