ADM: Anno Domini secundum temporem Martianum

BCM: Before Christ according to time on Mars

ERDAY: The days of the week named (in English) Tuesday, Wednesday, Thursday, Friday, Saturday follow after the 5 planets visible to the naked eye as seen from earth: Mars, Mercury, Jupiter, Venus, Saturn. From Mars, the 5 visible planets are: Earth, Mercury, Jupiter, Venus, Saturn. Thus, on Mars, we change the name for Tuesday to Erday (i.e. "earthday").