How many hours is one night on earth?

The actual period of night on Venus would be about 58.4 Earth days (half of the apparent sunrise-to-sunrise time of 116.75 days). Of course, you would not see sunset or sunrise from the surface, only a change from bright to dark to bright again after two months.

Although Venus has a rotation period (sidereal day) of about 243 days, its reverse spin and its shorter year (225 Earth days) combine to make for a shorter solar day.