Is there a math equation that can be used to determine what time it is on Mars?
Timekeeping on Mars is a little different from Earth, but not a huge leap.
The average length of a Martian sidereal day is 24h 37m 22.663s (based on SI units), and the length of its solar day is 24h 39m 35.244s (the latter is known as a sol, more precisely 88,775.24409 seconds). The corresponding values for Earth are 23h 56m 04.2s and 24h 00m 00.002s, respectively. This yields a conversion factor of 1.027491 sols/day. Thus Mars’s solar day is only about 2.7% longer than Earth’s.