Is there a setting in the menu for daylight savings time (may be abbreviated as DST)?
Some players require this setting to be adjusted rather than the actual time when switching between summer and winter time. If there is a DST (may be called "Daylight Savings Time" or "Summer Time") option, try changing the clock time back an hour (i.e. like if it was still on winter time) and then enabling the Daylight Savings Time option. This should in turn update the clock.