I had a nightmare last year, a squirrel got in my workshop and opened up a self service section with the sunflower seeds that were stored in there, right next to my timer. Little swine knocked the timer off the shelf, so I put it back without checking the timer on off switch, 3 weeks later I am wondering why my plants I just put in flower are still vegging and the others have started re vegging ffs.
Corrected that issue and about 3 weeks later added a new 600w light that came with a timer, so installed it all, checked the timer was set to on 
3 weeks later wondering why my plants are re vegging again lmao, the frigging timer that was brand new, was defective out of the box, the switch would not change it to timer on. Always test your new equipment before relying on it 