From UIL rulebook
Player Ejection – Section 1208 (i) (5):
(5) Player Ejection. Any player ejected from a contest is subject to an automatic penalty. The automatic penalty for such an ejection is as follows:
(A) Football. Ejected player misses the rest of the game in which they were ejected plus the first half of the following game. (Exception: Disqualification/ejection as a result of a targeting foul does not require the player to miss the first half of the following game.