I checked the Marriottvacationclub site and it appears that they have check-ins on Fri., Sat. and Sun for weeks owners. I use the "Helpful tools" to check the resort calendar and also the earliest reservation date.
So,
@burg1121, if (for example) you want to reserve Friday July 29, Sat. July 30, or Sun. July 31, you should either be on the phone or computer on Thursday July 29. 2021 at 9 am EASTERN. They open the entire week on that day.
I own some "white" or "gold" weeks in Palm Desert. So, since I live in California, I set the alarm, get a cup of coffee and am on both the phone and computer at 6 am Pacific (9 am Eastern) in order to reserve the high-demand Thanksgiving week. It is really high demand for gold owners because it is the only week that gives an Interval TDI of 125. I have succeeded in doing this for the past ten years. So,
@burg1121, I suspect that you need to adjust your technique. There is nothing wrong with checking daily for an unexpected cancellation, but you would have better luck being on the phone and computer at 9 am Eastern on "opening day".