This can be measured by the rotational speed of the planet and the distance it is away from the sun. These two variables must be known. after this you must then know where you are situated on that planet and its overall size and if its axis of rotation is inclined to the orbital plane to figure out exactly the length of a day.
Mercury=59 days venus=243 days retrograde earth=23 hours 56 minutes 4 seconds mars=24 hours 37 minutes jupiter=9 hours 55 minutes 30 seconds saturn=10 hours 40 minutes 24 seconds uranus=16.8 hours retrograde neptune=16 hours 11 minutes
The answer is different for each planet, and varies with the planet's rotation and its orbital period. Also there are two main definitions of "day".
The period of rotation is the "sidereal day". The time taken for the Sun to complete one daily apparent journey around the sky is the "solar day".
Mars is farther from the Sun than the Earth, so it takes longer to go around the Sun; in fact, its year is almost twice as long as ours. However, it spins on its axis at about the same rate Earth does, so our length of day is nearly the same.
Jupiter, although much larger than Earth, spins very quickly; its day is only about 9 hours and 55 minutes.
Here are the full details, with slight approximations:
Length of Sidereal day, followed by length of Solar day:
Mercury 58.65 Earth days. 175.94 Earth days.
Venus 243.02 Earth days. 116.5 Earth days. Notice that the Solar day is shorter than the Sidereal day, because Venus has "retrograde" rotation.
Earth 23.934 hours. 24 hours exactly.
Mars 24.623 hours. 24.660 hours.
For these planets both days are almost identical :
Jupiter 9.92 hours.
Saturn 10.66 hours.
Uranus 17.24 hours.
Neptune 16 .11 hours.
The length of a "sidereal" day (rotation period) is different on every planet. These are the approximate times:
Mercury 58.7 earth days, (multiply by 24 to get the day length in hours),
Venus 243 earth days,
Earth 23 hours 56 minutes,
Mars 24.6 hours,
Jupiter 9.84 hours,
Saturn 10.2 hours,
Uranus 17.9 hours,
Neptune 16.1 hours.
The length of the "solar" days are very similar, except for Mercury and Venus. For example Earth's solar day is 24 hours.
Solar day Mercury: about 176 Earth days,
Solar day Venus: about 116.75 Earth days.
It depends on what planet. Planetary rotational periods are nearly random (as opposed to orbital periods, which depend on the size of their orbit). For example, a day on Mars is fairly close to the same as a day on Earth (less than an hour difference), but a day on Jupiter is only about 9 hours long.
Mercury has a year of length 88 Earth days.
Mercury - Length of Year: 88 Earth Days | Day Lasts: 4222.6 Earth Hours (175.94 Earth Days)Venus - Length of Year: 224.7 Earth Days | Day Lasts: 2802 Earth Hours (2778 Earth Days)Mars - Length of Year: 1 Earth Year 322 Earth Days | Day Lasts: 24.6597 Earth Hours (1.02 Earth Days)Jupiter - Length of Year: 11.86 Earth Years | Day Lasts: 9.9259 Earth Hours (0.44 Earth Days)Saturn - Length of Year: 29.5 Earth Years | Day Lasts: 10.656 Earth Hours (0.43 Earth Days)Neptune - Length of Year: 164.79 Earth Years | Day Lasts: 16.11 Earth Hours (0.7 Earth Days)Uranus - Length of Year: 84 Earth Years | Day Lasts: 17.24 Earth Hours (0.7 Earth Days)Pluto - Length of Year: 248.5 Earth Years | Day Lasts: 153 Earth Hours (6.4 Earth Days)
The length of a year for each planet increases as each planet is farther from the Sun. The lengths are: Mercury: 88 days, Venus: 225 days, Earth: 365 days, Mars: 687 days, Jupiter: 12 years, Saturn: 30 years, Uranus: 84 years and Neptune: 165 years.
The planet you live on. Earth.
Venus. The length of "day" is 243 Earth days. That's the rotation period which is called a "sidereal day". However, there's also a "day" called the "solar day". That's the time for the Sun to complete one apparent journey around the sky. For that definition of "day", it is Mercury that has the longest day at about 176 Earth days.
Mercury has a year of length 88 Earth days.
It is approx 88 Earth-days.
The length of year on Mars is 686.98 Earth days or 1.88 Earth years.
It is about 117 Earth days (for the "solar day") or 243 Earth days (for the "sidereal day").
The year on the planet Mercury is very short. A year on this planet lasts 88 days compared to 365 days on Earth.
58.6 Earth days x 24 for hours
10 hours 40 minutes.
Venus' period of rotation is 243 Earth days. Its period of revolution is 224. 7 Earth days. The revolution period is the length of a year in Earth days on Venus. This planet is a terrestrial planet.
Mars period of revolution around the sun, its orbit, is 686.971 Earth days long, or 1.88 Earth years.
Venus, the second planet from the sun. One day on Venus would be equivalent to 243 Earth days. However, the length of a Venusian year is shorter at 224.7 Earth days.
Mercury - Length of Year: 88 Earth Days | Day Lasts: 4222.6 Earth Hours (175.94 Earth Days)Venus - Length of Year: 224.7 Earth Days | Day Lasts: 2802 Earth Hours (2778 Earth Days)Mars - Length of Year: 1 Earth Year 322 Earth Days | Day Lasts: 24.6597 Earth Hours (1.02 Earth Days)Jupiter - Length of Year: 11.86 Earth Years | Day Lasts: 9.9259 Earth Hours (0.44 Earth Days)Saturn - Length of Year: 29.5 Earth Years | Day Lasts: 10.656 Earth Hours (0.43 Earth Days)Neptune - Length of Year: 164.79 Earth Years | Day Lasts: 16.11 Earth Hours (0.7 Earth Days)Uranus - Length of Year: 84 Earth Years | Day Lasts: 17.24 Earth Hours (0.7 Earth Days)Pluto - Length of Year: 248.5 Earth Years | Day Lasts: 153 Earth Hours (6.4 Earth Days)
it takes 225 earth days to make on revolution around the sun