Planetary Time
How long is a day on Jupiter? How many Earth years pass in a single Pluto year? Explore the wildly different rhythms of time across our solar system.
Venus
Day Length
5,832 hours (243 Earth days)
Year Length
225 Earth days
Fun Fact
Venus rotates backwards (retrograde). Its day is longer than its year. The sun rises in the west and sets in the east.
Mercury
Day Length
1,408 hours (58.6 Earth days)
Year Length
88 Earth days
Fun Fact
A Mercury day is longer than its year. The sun rises, reverses, then rises again due to its eccentric orbit.
Pluto
Day Length
153 hours (6.4 Earth days)
Year Length
248 Earth years
Fun Fact
If you were born on Pluto, you would not celebrate your first birthday for 248 years.
Mars
Day Length
24h 37min (1 sol)
Year Length
687 Earth days (1.88 Earth years)
Fun Fact
NASA mission control operates on Mars time — shifting their schedules 37 minutes later each day.
Earth
Day Length
24 hours
Year Length
365.25 days
Fun Fact
Earth's rotation slows about 2 milliseconds per century. 600 million years ago, a day was only 21 hours.
Uranus
Day Length
17h 14min
Year Length
84 Earth years
Fun Fact
Uranus rotates on its side (98 degree tilt), so each pole gets 42 years of continuous sunlight then 42 years of darkness.
Neptune
Day Length
16h 6min
Year Length
164.8 Earth years
Fun Fact
Neptune has completed just ONE orbit around the Sun since its discovery in 1846.
Saturn
Day Length
10h 42min
Year Length
29.46 Earth years
Fun Fact
Saturn's exact rotation was only confirmed in 2019 using vibrations in its ring system.
Jupiter
Day Length
9h 56min
Year Length
11.86 Earth years
Fun Fact
Jupiter's equator rotates faster than its poles — different latitudes have different day lengths.
Day Length Comparison
All bars scaled relative to Venus (5,832 hours = longest day). Earth's 24-hour day is shown for reference.
Note: Pluto is classified as a dwarf planet by the IAU since 2006 but is included here for historical interest.