Which planet has a day longer than its year?

Venus is the planet that has a day longer than its year, and this is due to its unique rotational and orbital dynamics. A single rotation on Venus, which constitutes one day, takes approximately 243 Earth days. Meanwhile, Venus completes an orbit around the Sun, which constitutes one year, in about 225 Earth days. This means that a day on Venus is longer than a year on Venus by about 18 Earth days.

The planet's slow rotation is also notable because it rotates in the opposite direction to most planets in the solar system, a phenomenon known as retrograde rotation. While most planets, including Earth, rotate from west to east, Venus rotates from east to west. This retrograde rotation combined with its extended rotation period contributes to the distinct relationship between the lengths of its day and year.

The other planets mentioned do not exhibit this characteristic. Earth, for example, has a day of 24 hours and a year of about 365 days. Mercury rotates very slowly relative to its orbital period, but its day (about 59 Earth days) is still shorter than its year (about 88 Earth days). Neptune has a day of approximately 16 hours and a year of about 165 Earth years, making its day significantly shorter