I did just check the date on the jug and this box says Feb 17 2022.So close. 4 times, twice.Every 2-3 hours is the preferred frequency. Life gets in the way but the longer the pool stays below SLAM level, the longer it takes.
+1. It's wise to do an occasional verify during SLAM after adding. Once it's over, every dose needs to be verified after, but doing so during a SLAM would eat too many supplies.