The only code with timezones should be the bit squishy meat bags touch. Everything’s is should be UNIX time. Or it you are unfortunate enough to be on Windows, NT time.
Some unfortunate programmers already have to deal with the speed of time not being a constant. In a distant future, timestamps might always have a universal position (and speed), and is that much different from timezones?
Or we find some way of removing time distortion of physics. Find the universe’s real systick. 😃