Something changed the timers

     We have two lamps that sit in the two front windows. They are set to come on about dark and go off about dawn. The same timer operates both lamps. The timer has tiny pin like projections, each representing about 30 minutes of time. Fot the lamps to come on all of the pins between  7:00pm until 7:00am are pushed in. These pins are small and require some force to push them in. The lights have worked the way they are supposed to for several years now. Yesterday, my wife noticed the lights in the windows were on in the middle of the afternoon. Thinking an electrical blackout may have occurred in the night; she just figured she'd have to reset the timer; but as she was busy at the time she put it off until later. Later while doing something in the Diningroom she noticed the Parlour window light go off.  So she figured she'd better reset the timer. Upon inspection she first noticed that the timer was at the correct time. Further inspection indicated that two of the pins in the afternoon section of the timer were pushed in. She certainly hadn't pushed them in, I didn't push them in' The dogs hadn't even been in the parlour for days (how would they push in two tiny pins anyway)? The timers are well off the floor. There probably is a mundane answer for this; but I haven't discovered it yet.