Regular users can share calendars with regular and external users, collaborators, and user groups, unless their access role restricts them.
Navigate to the relevant calendar.
Right-click the calendar that you want to share.
Select Share from the menu that appears.
Start typing the name of the user you want to share the calendar with in the search bar and select them from the drop-down list when they appear.
Full: all user rights available.
Editor: user can add tasks to the classic calendar and share/unshare the calendar.
Read-Only: user can view the calendar but can’t make changes or share the calendar with other users.
Your calendar and all its layers are shared with the selected users.