Sony CBK-RPU7 Operating Instructions Manual page 27

Note
Always connect to an AC adaptor (AC-DN10A) for operation. If a battery is installed, operation will continue
if the AC power supply is subsequently disconnected.
Time tab
This tab is used to set the date and time.
Only users with Maintainer role can change settings.
When [Daylight Saving Time] is set to [Manual Dates]
27