Yes, you can!
If you are the owner of a calendar and would like to transfer it to another user, before anything else, make sure this user has already joined that particular calendar.
Then, in the Calendar Options tab of the Calendar settings page of your calendar, select this collaborator and click the red "Transfer" button. Your calendar will be transferred to your collaborator, and both of your subscriptions will be updated accordingly.
📝 Note: you can only transfer calendars to users who have an active Loomly subscription i.e. the Owner of the Loomly subscription