Before the answer is given, you must realise just how slow slowing down is. It won't mean an abrupt stop today, tomorrow or the day after tomorrow. The rate at which the Earth is slowing down is miniscule, you won't even notice it. We're talking in the magnitude of millionths of a second. It would take 140 million years before the length of the day became a 25 hour day, we'd be long gone unless of course this website has been archived for life and still read.
The Moon is moving away from us at about 3 cms a year and the moon has been a stabalising effect on us. The moon was discovered to be moving away when N.A.S.A. conducted an experiment by placing mirrors on the moon and then timing how long they took to be returned. The Moon is said to be a factor in why our planet is slowing down.
At the very beginning when the Earth was very young. The Earth would've been rotating very fast, talking a few hours or so. Fast forward a few (cough, hundreds) million years to the age of the Dinosaurs. When the dinosaurs ruled the planet, the planet was rotating at a speed that is greater than it is today. A day would have been longer than 21 hours but less than 23 hours. Either way, the day for a dinosaur would have been shorter than it is today. A.B.C.
If you go back further in time, say 620 Million Years ago, the day would have been about 21 days. 620 Million years ago equates to the Vendian Period when there was life on the planet but not as we know it. In the Vendian Period, there was only microscopic bacteria and algae according to fossilised records. Berkeley
There is a theory and it is only a theory that says next year (2018), the Earth will experience a lot more earthquakes than it did the previous year. In 2016, there were 14,421 geological earthquakes. Most of those earthquakes were so minor that they were never reported in the media. The only way you would know about them if you weren't from the quake community is from the media. Being, not from the quake community, i got the figure from Wikipedia.
The Earth day is extending by 1.7 milliseconds a 100 years. If the Earth continued onto forever, the Earth would stop spinning in about 1.9 trillion years. The Sun is expected to have gone supernova in five billion years and life on Earth will have been wiped out in a billion years time when the Sun starts to turn into a red giant as it depletes it hydrogen fuel and moves into the next stage of evolution. Hopefully by that time, we'll have moved off and colonised other planets. Whats Up With That?