Universal, no. But the Darian calendar system has been carefully devised to fit Mars, the moons of Jupiter, and Titan, and as far as i know that's the closest a

Universal, no. But the Darian calendar system has been carefully devised to fit Mars, the moons of Jupiter, and Titan, and as far as i know that's the closest anyone has got: http://ops-alaska.com/time/gangale_mst/abstract.htm http://ops-alaska.com/time/gangale_mst/abstract.htm