A day on Mars, called a "sol," is approximately 24 hours, 39 minutes, and 35 seconds long. This makes it about 39.5 minutes longer than an Earth day, which is 24 hours long. The Martian sol is equivalent to roughly 1.0275 Earth days

. Mars also has a sidereal day (rotation relative to distant stars) lasting about 24 hours, 37 minutes, and 22 seconds, which is slightly shorter than its solar day (sol)

. In summary:

• Martian solar day (sol): ~24h 39m 35s
• Martian sidereal day: ~24h 37m 22s
• Difference from Earth day: ~39.5 minutes longer

This sol length is important for mission planning and human adaptation to Mars time cycles