'On that Day' in the Bible

And they gathered together to Mizpah, and drew water, and poured it out before Jehovah, and fasted on that day, and said there, We have sinned against Jehovah. And Samuel judged the children of Israel in Mizpah.

And as Samuel was offering up the burnt-offering, the Philistines advanced to battle against Israel. And Jehovah thundered with a great thunder on that day upon the Philistines, and discomfited them; and they were routed before Israel.