This Block Number feature has been made for companies receiving lots of inbound calls, e.g. emergency call centers, to be able to block spam calls from e.g. a mentally ill person for a given period, e.g. for 5 minutes or ½ hour. But since you must not block constantly, there is an option here to specify an overall fixed time interval for these blocks.
Simply click the checkbox to enable → type in a duration of time → remember to click Save.
The time until the number will be unblocked will now be forced to the time set in the Block Settings.
Find more Admin Settings info in the posts below