[RedNifre]

No, Mars has less mass than Earth, so if you use Earth UTC, Mars seconds will be longer than SI seconds, which does not seem like a good idea.

[skissane]

I think you misunderstood my point - I was saying make both Earth UTC and some Martian time scale available, just use a new API and data types for the latter. Which one to use in any given use case will be up to the application developer.