It's not easy to tell because of the floppy gaseous nature of the planet but last year they think they cracked it at 10 hours, 34 minutes and 13 seconds
5
Circumference of a sphere = 2*pi*radius or diameter*pi
Mars.
the length of day on earth is 24 hours
Mars
The length of the day in th US is the same as the length of the day anywhere else in the world, roughly 24 hours.
the length of a day on Jupiter is average, 9.9 hours
the length of the day is not a fixed unit of time
See answer given for length of Venus day in hours.
The length of a "day" on the moon is 29 Earth days.
During the Autumn equinox the length of the day and night are nearly equal. The length of the day on the equinox is approximately twelve hours.
Mars has a day of 24 hours 39 minutes and 35 seconds