How many days are in a Martian month?

Answer 1

First Answer:

Here on Earth, the original definition of "month" was one Moon-cycle, about 29 days. (It has since been re-defined, and for the Gregorian calendar at least, has no real connection to the lunar cycle.)

On Mars, there are two moons, Deimos and Phobos, both very small and fairly close. There isn't any real analogue to "month" for Mars, and there won't be until humans move to Mars and establish one.

Second Answer:

Our word "month" comes from moon. On lunar calendars there are 13 "moonths" per year, since it takes the moon about 27 days to orbit the earth. 365/27 = 13.5. This makes lunar calendars slightly awkward. So we reduced the number of months by making them three to four days longer, twelve months per solar year.

Mars has two tiny moons, Phobos and Deimos. These would appear about like bright stars when full. Phobos is larger and orbits very close to the Martian surface. It orbits so fast it appears to rise in the West and set in the East in only four hours, as viewed from a single point on the Martian surface. Since the Martin day is slightly longer than Earth's day, if we based the Martian Month on the orbit of Phobos it would be about a third the length of the Martian Day (almost 8 hours). In other words, there would be three martian months each martian day.

Answer 2

Rotation period (sidereal day) about 24 hours 37 minutes.

Solar day about 2 minutes longer.