The format strings (timezone related) %z %Z appear only supported in std c++ for
But they both make similar sense. And the support in the current stdc++ lib is unfortunate (for Stroika) because it refers to the global system time (or maybe based on TZ)
Instead, the right thing for the DateTime class - with its PARSE and FORMAT methods, would be to use its associated timezone.
For BOTH Parse() and Format() - this can be done relatively easily by ourselves parsing the format string (%A %B etc) - and for nearly all of them, just calling the time_put/time_get variant to handle the string, but for the %z %Z strings - we handle directly.