Naming something that only works on one planet "Universal Coordinated Time" was a mistake.
The scifi series Babylon 5 with its titular station used Earth Standard Time [1] while being placed in Epsilon Eridani system. That doesn't sound bad, I think.
The another issue the future colonists will have to deal with will be how to track days, months and years. There's Thomas Gangale's suggestion that does look interesting [2].
[1] - https://babylon5.fandom.com/wiki/Earth_Standard_Time [2] - http://ops-alaska.com/time/gangale_mst/darian.htm
Why? There's plenty of computers in Mars right now and they use martian time already [0]. It's not as if OpenBSD have invented anything new, they just adapted the OS to existing practices.
Now, if we'd be there already for decades or even centuries with permanent settlement then perhaps we'd have some date and time formats that would be similar to what we're having on Earth (or maybe they'd use the exotic decimal time) and I wouldn't be even writing the parent comment in first place.
Well, these people can use OpenBSD now ;)
Considering that the weather outside will kill you year-round on Mars, debate is of course rather academic...
Mars is the least useful planetary body in the Solar System for human colonization, so that time may well be "never".
I suppose you could construct criteria and assumptions that would support that conclusion, but I can’t see a reasonable set where that works out.
The problem is that there is nothing useful on Mars and its location sucks. Any other planetary body makes more economic sense.
There’s nothing worth the shipping cost anywhere off the surface od the Earth, and all the rest of the planets are much worse locations than Mars. (Venus maybe slightly better if you are only getting to/from high atmosphere, but that has the “there’s nothing worthwhile there” problem more than Mars does.)
Or composition; its also not easier to reach (or return from) if you are going to the surface.