mars-sim VS yamcs

The Darian calendar is one which is already proposed to do this, and scientists involved with the rovers live off of Martian time (0:00-24:00 method), half a sol out of sync with the rovers (commands are given in advance, so they prepare commands and receive/review data when it is night for the rovers). The Java Mars Simulation Project uses a modified Utopian Calendar from the Mars Society (this uses a different epoch from the Planetary Society's version), but also uses millisols for time of day rather than the 24 hour method, the 24 hours + witching "hour" (actually closer to 2243 seconds) used in the Mars Trilogy, or the 0:00-24:37:22.663 method. I personally would like to see a calendar loosely based off of the French Revolutionary Calendar be used (for both Earth and Mars). For both, the year would be divided into ten months, nine of which would be equal. On Earth, nine "months" would be forty days long, and on Mars, nine "months" would be seventy sols long. In both instances, "weeks" would be ten-days long except for people opting to use religiously-defined weeks (on Mars it would not align with Earth anyway, so religion and ambiguity is the only reason to keep using seven). Length of time would be measured with seconds and kiloseconds and so on, but time of day would be measured by permille of the day complete, similar to the Mars Simulation Project's millisols. For Earth, if a year is divisible by 4 but not 128, it would be a leap year (with very rare exceptions to keep the start on the equinox on average), making the last "month" 6 days rather than 5. For Mars, if a year's remainder when divided by five is 1 or 3, or if the year is divisible by 125, then it would be a skip year (last month is 39 instead of 40 sols).

OpenMCT is great if ALL you want is to do is look at Telemetry. But good luck if you want to send a commamd to a vehicle. I think YAMCS is much better solution: https://github.com/yamcs/yamcs

Yamcs has got a builder for displays, client APIs, etc. Almost everything you'll ever need.