Here is a new planet with instrumentation sent by humans with the necessity to create a timekeeping system with its own features that are not arbitrary like a leap day correction within a Martian year, a Martian 24 hour day/night cycle anchored to noon with an integer of hours reflecting 15 degrees geography/geometry and all the other things that work so well on Earth.

The group of people who can't manage to grasp that the average 24 hour day has to come first before anything else is timed using equable hours, minutes, seconds or other subdivisions will, in future, represent a regrettable subculture.

The first procedure to creating a Lat/Long system for Mars where time and location are fixed as the system is on Earth, is the determination of the average day by anchoring the observation to noon as noon is always symmetrical to the appearance and disappearance of the Sun regardless of hemisphere or season.

https://adcs.home.xs4all.nl/Huygens/06/kort-E.html

It is sufficient to ascertain the average 24 hour day on Mars even without the creation of a calendar framework in order to keep Martian days fixed closely to the orbital points of Solstices and Equinoxes.

Timekeeping on Earth developed in stages, however, it is possible to operate with the natural noon cycle first on Mars by employing the Earth's 24 hour timekeeping system in discerning noon. The original proposal of Huygen's in terms of sunrise/sunset is perhaps one of the better approaches.