Question about Lexon Flip Classic

Hello my alarm clock is set with time zone plus 1. it has the right time during the day, also in the evening. but in the morning it wakes me up 1 hour too early, yesterday and also today. it then has the wrong time, instead of 7 it has 8 o'clock and therefore wakes me up too early. yesterday and also today. but the time is right when I go to sleep in the evening. What's going on?