It'd be not-so-funny if there was a miscalculation and the Earth was slowed down or sped up too much. There's a story about the end of times and the Antichrist (Dajjal) in the Muslim traditions where this sort of thing actually happens. It is said that the "first day of the Antichrist will be like a year, the second day like a month, and third like a week", which many take literally, i.e. a cosmic event which actually slows down the Earth's rotation, eventually reversing course such that the sun rises from the West (the final sign of the end of humanity).