Time zones weren’t established to adjust for north/south variances, they’re for east/west. And we don’t adjust the clocks to make sunrise and sunset fall on consistent time of day throughout the year. They’re so that we can reliably account for what the local time is somewhere other than where we are (in the USA they were created for cross-continental railroads to publish train schedules). We already have GMT/UTC and every other time zone is defined relative to that, so why don’t you just personally use that in all your own devices and communications already? Nothing but you can prevent you from doing so.