The spin of the Earth starts slowing down dramatically. It is estimated Earth would stop spinning in as little as 5 years. The first effect is the isolation between the Global Positioning System satellites and ground-based atomic clocks. Then the all-day, all-night stock markets crash because the day is longer than 24-hours. As times goes on the oceanic bulge of water at the equator moves northward and southward. The water floods Russia, Canada, and Antarctica. The atmosphere, once shaking solar heat out over the world and shifting air, stops and whirls to the poles. The air starts to thin at the equator and people have to migrate to more northerly and southerly cities in order to keep up with denser air. There is a higher risk of ultraviolet radiation as the electromagnetic field weakens because of the slowing inner core. The slowing Earth causes friction between the crust and the inner and outer cores, creating tremendous earthquakes.
Humans and other animals start suffering from sleep fatigue as their bodies cannot properly work in a day longer than 60 hours.
The new oceans at the poles start flooding most of North America and Mediterranean Europe around this time. As the oceans have moved to the poles, the sea-bed dries out, revealing new land.
Eventually, the Earth stops spinning altogether. The scorching light of day lasts for six months, while the remaining six months of the year are ice-bound darkness. So this is when earth stops spinning.