How long is a day on Mercury?
Data as of July 2026
176 Earth dayssunrise to sunrise
A day on Mercury lasts 176 Earth days from one sunrise to the next, even though the planet spins once on its axis every 58.6 Earth days. That is 176× an Earth day.
▶ Watch Mercury turn in 3D
Why Mercury's day is so long
Mercury spins once every 58.6 Earth days, but it is also racing around the Sun, and the two motions nearly cancel. From the surface, sunrise to sunrise takes about 176 Earth days: two full Mercury years. Stand in the right place and you would even see the Sun rise, stop, set briefly and rise again.
Sunrise to sunrise
176 Earth days
One spin (against the stars)
58.6 Earth days
Compared with Earth
176× an Earth day
Mercury days in its year
0.5
Its year
88 Earth days
Distance from the Sun
0.39 AU
Day length on every world
| World | Day (sunrise to sunrise) | One spin |
|---|---|---|
| Jupiter | 9 h 56 min | 9 h 56 min |
| Saturn | 10 h 39 min | 10 h 39 min |
| Neptune | 16 h 7 min | 16 h 7 min |
| Uranus | 17 h 14 min | 17 h 14 min (backwards) |
| Earth | 24 h 0 min | 23 h 56 min |
| Mars | 24 h 40 min | 24 h 37 min |
| Pluto | 6.4 Earth days | 6.4 Earth days (backwards) |
| Venus | 117 Earth days | 243 Earth days (backwards) |
| Mercury | 176 Earth days | 58.6 Earth days |
Earth's spin, against the stars, takes 23 h 56 min; the extra four minutes to a 24-hour day come from Earth moving along its orbit while it turns. On Mercury the same effect is enormous.
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✓ Facts verified July 2026
Every figure on this page is a real, rounded value checked against primary sources. Found something out of date? See how we keep it accurate.