I mean, that’s just physics for you. Because gravity influences time, any extraterrestrial colony is going to have at least a slight difference in a seconds duration compared to earth.

For the average person, the slight difference in the length of a second will probably be unnoticeable. Any differences would likely be overshadowed by the length of a day, season or year, assuming the planet in question even experiences those naturally. For an example, tidally-locked planets don’t have natural days.

It would potentially pose problems for time-sensitive scientific research. However, that could be resolved by creating an independent time standard based on outside phenomenon, like pulses from a neutron star, and then creating conversion tables for different colonies. I’m guessing that might be what NASA ends up doing, though there could be issues with that method that I’m unaware of.