If you are working on the event with several people, you can give your colleagues (possibly limited) access to your organization.
Click on the GEAR at the bottom left and open: 'Organization settings'.
Click on the ORANGE button at the top right: (Customize your organization name)
In the extra menu go to TEAM
Click on invite
Fill in the email address and select a desired role
Click on invite again and the invitation will be sent. Your colleague will automatically receive an email asking him/her to create an account.