You can schedule content export to run at a regular frequency by selecting Recurring Export (Figure 1):
Figure 1 Recurring Export
Note: The default value is 24 hours, starting at 23:59:59 UTC. When programming your download process, please wait for the job to complete before retrieving the file
You can also export content manually by selecting Ad-hoc Export based on a date range, but it should not be run at the same time as a recurring export. The ad hoc export will contain data from 00:00:00 to 23:59:59 GMT on the selected dates.
Refer to the Knowledge Article found here on how to perform an ad-hoc content export.