OUSTON - The phrase ''day to day'' is one of the most often used - and misused - in dealing with a player's availability. In the case of Rockets' star guard Steve Francis, however, it is right on the money. ''Hour to hour'' might even be more accurate.

Each day he wakes up, he has no idea if he'll be able to play or practice. That was the case again yesterday. He woke up with a migraine, a condition that has forced him to miss five games already. He did not attend the morning shootaround.