Not so much a light leak, as a light flood...

So I'm not sure how my cats did this, but they pushed down the pins on my timer, so I got up at 3a.m and notice my lights on (Flowering darkness is 9pm-9am). And we went to bed around 11 so my plants have had their darkness interrupted for a possible 4 hours. What I'm wondering is how worried I should be? Is a constant light leak worse then just once (400w HPS), and assuming this never happens again, should my plants safe from adverse effects?

Thanks in advance!

Light just breaks down the flowering hormone, the more exposure the more degradation you get.. simple as that. 4 hrs, not so bad... 40 hrs, kind of a big deal. The moment it's (relatively) dark again the plant can manufacture more hormone.