Twice
it spins prograde
Mars spins faster that was because it then tilted at an angle.
One spin is what measures the length of one day
Which planet?
Mars takes about 24 hours and 39 minutes to rotate.
Once every 24 hours 39 minuet's.
Earth spins on its axis for about 365/366 times while it completes one journey.
The sidereal rotation period of Mars - one spin on its axis relative to background stars, is 24.623 hours. This is very similar to the earths sidereal rotation period.
Mars takes about 24.6 hours to complete one full rotation on its axis, which is slightly longer than an Earth day.
24 hours 37 minutes and 23 seconds. From my geology 305 hand-outs.
According to Nasa.gov, one day on Mars is 24hr, 39 min, and 35 sec.
Mars spins on it's axis in a very similar time to an Earth day. It takes about 24.6 (24.6229) hours for Mars to spin on it's axis. That is about 1.025 earth days.