By default, your monthly optimization occurs on the same day of each month. This date is based on the date you initiated your first optimization. For example, if you began your first optimization on May 5th, then your subsequent optimizations will occur on the 5th of every month (i.e. June 5th, July 5th, August 5th, etc.).

You will be able to see the date of your next scheduled optimization on your Max Dashboard. In the upper-right corner of your screen, you’ll see a dark box labeled “Optimized Savings.” At the bottom of that box you’ll see the date of your next scheduled optimization.

If you have elected to either Suspend Optimizations for a specific amount of time, or you have chosen On-Demand Optimizations, you will have the option to turn Automatic Optimizations in this place instead of your next scheduled optimization.

You may change the day of the month on which your monthly optimization occurs, suspend optimizations until a future date, or choose On-Demand optimizations by editing your Optimization Schedule:

How can I change my optimization schedule?