Looks like USACO just released their 2020-2021 schedule: http://usaco.org/
Dec 18-21: First Contest
Jan 22-25: Second Contest
Feb 26-Mar 1: Third Contest
Apr 2-5: US Open
TBD (Late May): Training Camp
Jun 20-27: IOI 2021 in Singapore
Looks like USACO just released their 2020-2021 schedule: http://usaco.org/
Dec 18-21: First Contest
Jan 22-25: Second Contest
Feb 26-Mar 1: Third Contest
Apr 2-5: US Open
TBD (Late May): Training Camp
Jun 20-27: IOI 2021 in Singapore