Obviously what we need is no time zones and one standard time around the globe where:

1 second = 1 second

100 seconds = 1 minute

100 minutes = 1 hour

10 hours = 1 day

100 days = 1 year

...and ignore that light in the sky. Only farmers need to know about that light.

Swatch tried to do something like that in '98:

https://en.wikipedia.org/wiki/Swatch_Internet_Time

Instead of hours and minutes, the mean solar day is divided into 1000 parts called ".beats". Each .beat is equal to one decimal minute in the French Revolutionary decimal time system and lasts 1 minute and 26.4 seconds (86.4 seconds) in standard time. Times are notated as a 3-digit number out of 1000 after midnight. So, @248 would indicate a time 248 .beats after midnight representing 248/1000 of a day, just over 5 hours and 57 minutes.

There are no time zones in Swatch Internet Time; instead, the new time scale of Biel Meantime (BMT) is used, based on Swatch's headquarters in Biel, Switzerland and equivalent to Central European Time, West Africa Time, and UTC+01. Unlike civil time in Switzerland and many other countries, Swatch Internet Time does not observe daylight saving time.

The French Revolutionaries had that. Well, they did acknowledge the primacy of the physical day and year.

https://en.wikipedia.org/wiki/Decimal_time

There's two lights, Mr. (or Ms.) Smart-Aleck! !! !!!

And who wins depends on how fast you're going while watching.

I could imagine a system where any date or time information coming into your eyes or ears would automatically be translated to your preferred time offset. All you would need to do is decide which system of time you wanted and the computer would ensure you always perceived this. As you speak about time, someone else hears their preferred time system in your voice. Emails and other text-based methods are simple, analog and digital clocks could be updated on the fly with computer vision techniques and machine learning.

So a seamlessly realtime audiovisual AR system that's cheap and convenient for anyone to adopt? Unless and until that ever happens, we're stuck with lower-tech solutions like time zones.

timezone aware Babel fish.

Thankfully now we have satellites and atomic clocks so that there is a consistent time across all places.