So this "phenomena" was observed elsewhere?
The claim that Velikovsky makes is that in many other ancient peoples myths and folk law the same incident was written about, but from their perspective, so some writings have claims of unusually long nights, some writings claim that dusk lasted for a prolonged time. He also links his claim into the 'fact' that the actual calendar changed around this time as well, being that many nations counted 360 days for a year, Velikovsky claiming that at that time the rotation of the earth changed dramatically also. He also links into the equation that in the biblical account more people died from the hail than from the sword and attributes this to the cause of the sun standing still.
His books are a very interesting read, although quite a lot of his claims have been proved false, although some of the claim he made proved true, but were very controversial to the science of his day. Fascinating to look into though…..