Mercury's rotation period is about 59 Earth days. This means that one day on Mercury (one complete rotation on its axis) takes approximately 59 Earth days.
Mercury rotates once on its axis about every 58.6 Earth days.
Mercury's year is 88 Earth days. This is the time it takes to go around the sun, (not to rotate on its axis).
It takes about 59 Earth days for Mercury to rotate once on its own axis, so in 1 day on Mercury, it rotates only a fraction of its total rotation.
Eris takes approximately 550 Earth years to rotate on its axis.
About 28 days.
16.11 hours.
365 and 1 to 4 days