Well, I'm just thinking that if you output a timestamp that looks like:

2015-09-03 14:33:04 MCK+4

Then later try to parse it back, your software might interpret MCK+4 as a POSIX string (I know that python-dateutil would), since it's formatted like one.

On May 26, 2016 10:56:02 AM EDT, Random832 <random832@fastmail.com> wrote:

On Thu, May 26, 2016, at 10:33, Paul G wrote:
 Wouldn't MCK+4 be interpreted by a POSIX TZ variable as 4 hours behind
 UTC?

Why is someone going to paste the abbreviation into the TZ variable?
There are very few timezones for which that would yield a useful result.