If it happened suddenly, there would be massive tidal waves on western coasts.
The sun would rise in the west and set in the east. Timezones would be backward. People in different areas would have oddly desynchronized sunlight exposure relative to the time on their clocks. For example, if this happened at sunset for you, the sun would rise first from the east and set in the west, then rise again from the west and set in the east. You’d be halfway through a double day at the moment of switching. Other people would have a double night.