Despite this, I'm an advocate for martian self-determination when it comes to deciding their timekeeping system. Earthlings, despite their good intentions, should stay out of the matter categorically.
Will you be singing that tune when a religious minority you hate moves there, establishes a theocratic government, starts teaching women to read, hanging undesirables and troublemakers and regressing on pretty much every human right your ancestors died for, bonus points for starting a war with the locals.
That said, in the historical example I'm referencing the state was too weak to do much about them from afar and they did clean itself up after subsequent immigration diluted their culture over the following 100yr. God what a bunch of assholes they were in the meantime though...
You'll be happy to know that you can appreciate their input on Earth matters as much as they'll appreciate yours on martian matters.
Does everyone on the ISS stick to the same time zone? Or do they tend to sleep with their country of origin?
UTC for everyone.