Frequently, but it's a bit harder than that. Days on different planets don't have 24 hour durations. Try and adapt that to every date library ever. I work on

Frequently, but it's a bit harder than that. Days on different planets don't have 24 hour durations. Try and adapt that to every date library ever. I work on display libraries for multiple projects including MSL, and the standard solution is to use "slow seconds" and force Mars days to be 24 hours. I did ask moment.js how they might support Mars time and didn't get far. https://github.com/moment/moment/issues/2391 https://github.com/moment/moment/issues/2391