I don't know the answer ... But it reminded me of an article I heard on NPR the other week.
Seems the Earth used to have more days per year ... But the drag of the Moon is slowing down the rotation of the Earth.
What planets have days that are longer than years and what would their calendars be like?
Mercury faces the same side toward the sun at all times. This results in one rotation -a day- being equal to one revolution around the sun -a year.
In the case of Mercury, this is 88 earth days.
hmm not sure.
That would depend on that particular planets length of years. From here, I don't think its possible.
