Information
It is possible to automatically set the date and time on devices running iOS 12 and later. The time zone updates only when the device can determine its location, such as when a device has a cellular connection or a Wi-Fi connection with location services enabled.
Rationale:
Correct date and time settings are required for authentication protocols, file creation, modification dates, and log entries.
Impact:
When this option is enabled, users can't turn off Set Automatically under General > Date & Time
Solution
Open Apple Configurator.
Open the Configuration Profile.
In the left window pane, click on the Restrictions tab.
In the right window pane, under the tab Functionality, check the checkbox for Force automatic date and time.
Deploy the Configuration Profile.