You have the ability to set personal preferences for your Loops. First, navigate to Settings >> User Preferences >> Loops as shown below. You can also access the Loops Settings page via this link.
Now, you're able to make easy changes to the following:
Time increments for interview duration options
Default interview duration
Default candidate availability
Enable or disable the option to mute calendar invite notifications
Enable or disable the option to mark calendar invites private
Enable or disable the option to mark invites private by default.
Click "Save" and you are good to go!
Please note: Users can only update their own preferences. They cannot update other users' preferences.