the time it takes the earth to spin around on its axis
The speed of rotation of the Earth and its axis tilt. The latter causes the basic daylength to change as the seasons change.
It is the rotation of the planet one complete revolution that determines the length of a day.
29.5 earth days is one moon day wich is the length of the moons day
The length of a day is based on the average period of time required for one rotation of the earth on its axis.Read more: The_length_of_a_day_is_based_on
243 earth days
Earth rotation
One day on Mercury is equal to 1407.6 Earth hours.
One Mercury Day is the equivalent of 59 earth days.
One spin is what measures the length of one day
WELL THE LENGTH OF THE DAY IS RELATED TO THE Rotation AND REVOLUTION OF THE PLANET BECAUSE THE PLANET HAS LENGTH BUT IT MIGHT NOT HAVE THE SAME THING AS OUR LENGTH AND IT HAS THE SAME ROTATION AND REVOLUTION.WHAT DO YOU YOUNG GUYS AND LADIES THINK ABOUT MY ANSWER ?PLEASE COMMENT ON IT I WILL APPROACHED THAT BY.
Mars has a similar day length to Earth, a little longer at 24h 39m 35s (apparent solar day).
The planet's rotational period is the only thing that determines the length of one day. (mostly - it also is dependent on how fast the planet orbits the sun. If it orbits quickly, the "day" will be measurably less than the time for one full rotation.)
Mars's day-length is close to that of Earth: 24.7 hours. As such, there are 1.03 Martian days per every one Earth day; or, alternatively, 0.97 Earth days per every one Martian day.