Because if you have anumber that is more than 1 you have to add an s. EXAMPLE: 31 HOURS 31 hour witch makes sense? * * * * *witch? what have witches got to do with this? Maybe it WAS a witch that...
There are areas on Earth that can receive 24 hours of day and 24 hours of night - but not at the same time. North of 66 1/2 degrees latitude N. (the Arctic Circle) will receive 24 hours of sunlight...