From the Author&Monitor - Manage - Author - Triggers section in the Azure Data Factory you can edit the trigger schedule for Daily Scheduled Run:
Open the Daily Scheduled Run trigger and view the schedule:
From this view you can change the Start date/time and the recurrence schedule.
If you make any changes, click OK to close the Edit view, and then click Publish all to commit the changes to the service.
Note: If you change the Recurrence, the result might be added cost.