I believe you are thinking of Venus.
However a day on Venus is 243.0185 days, not hours.
244 hours
24 hours
The outer planets have longer rotation periods than the inner planets. For example, a day on Jupiter, an outer planet, is about 10 hours long, while a day on Earth, an inner planet, is about 24 hours long.
One day on Haumea, a dwarf planet in our solar system, lasts about 4 hours. Haumea rotates on its axis very quickly compared to other planets and dwarf planets in our solar system.
No, not all planets in our solar system have days that are 24 hours long. For example, Venus has a rotation period longer than its orbital period, resulting in a day that is longer than 24 Earth hours. In contrast, Jupiter has a fast rotation speed, leading to a day that is about 10 hours long.
Mercury.
On Earth there are 24 hours in the day. There are 24hrs in a day. On different planets, it may vary.
Which planet?
An uranium day is approximately 243 Earth days long. Due to its slow rotation, Uranus has one of the longest day lengths among the planets in our solar system.
Yes, all planets that we know of have at least some spin - their rotation on the axis being the planet's day. In our solar system Jupiter spins the fastest - with a day under 10 hours long.
Mercury, has 24 hours in a day, the same as the earth and all the other planets in the Universe.
Of the four inner planets (Mercury, Venus, Earth, and Mars), Earth has the shortest day at 23 hours and 56 minutes sidereal rotation period. That's the "sidereal day". The day that lasts exactly 24 hours is called the "solar day". For both "days", Earth has the shortest day.