How to select rows in dataset based on dates?

I have a dataset and can not figure out how to select rows by date like <01/01/2021. I am missing some key as I have Googled but can’t find correct way. So. in other words find for example all rows that are <= 12/01/2020.
Thanks.
David
The dataset columns look like:

check out this se article: https://mathematica.stackexchange.com/questions/166522/selecting-a-range-of-dates-from-a-database

Wow, that worked! I really appreciate the answer! I never would have figured that out. Now to break apart what it is doing so I really know it! Thanks.