We typically have users working with Google Calendars, so I did some digging for Apple Calendars.
I noticed that when I imported my Cal code from Apple, I had the same problem! So I followed some instructions I found, and found out that although my local calendar is set to Eastern (where I live), my iCloud Cal was set for Pacific.
Can you go to
And log in
Then, click on your name in the top right
Adjust your timezone as needed
You can also click on the system preferences there and turn on Time Zone Support, then refresh your calendar, and give it a few hours to sync:
We are troubleshooting together, so please let me know the result after a few hours, once the calendar has had time to sync back up.