Most things that set the time like that receive a signal with the which the clock understands, but the signal is constant throughout the year, unless the clock knows the date and has been told to adjust to winter time it won't do it (it needs to know the date to know when, not all countries adjust their clocks for winter so it needs to be told to do it, if it can't be told or doesn't know the date, or both it needs to be done manually).