Hi Carsten,
Thanks for contacting us!
You can update/change how often the import runs by editing your scheduled import.
Every scheduled import can be located on the Events > Import screen by clicking on the Scheduled Imports tab.
On the Scheduled Imports tab, hover over the import and it will reveal additional actions. Select the option to Edit.
You can set your scheduled import to run every 30 minutes, every hour, daily, weekly or monthly.
I hope this helps! Let us know if you need anything else!
Have a nice day!
Patricia