You can export your customers to a CSV file by clicking on the arrow button 
next to Options (see screenshot).
As soon as you have clicked the button, you will receive an e-mail with the link do download the csv file.
Click here to go directly to the Customers menu item of your calendar
exported data are:
| columnname | description |
| first_name | First name (e.g. Max) |
| last_name | Last name (e.g. Mustermann) |
| gender | gender (male or female) |
| email (e.g. max@gmail.com) | |
| mobile | mobilephone number |
| birthday | birtday (e.g. 31.12.1988) |
| adress_street | street and house number |
| adress_postal_code | zip code |
| adress_city | city |
| additional_attributes | creates a customer note with this content |
| tags | If you have added customers to specific groups. Multiple groups are separated by comma (e.g. VIP, Teenagers) |