I Spent The Money On High Pressure Sodium Lights ...now What?

I just recently bought the high pressure lights, 430 watts for 10 plants in a 3'X3' closet set up, but i can't seem to ever remember to turn them on and off for the 12/12. and i know i should just buy an outlet timer but the door and light blocking sheeting need to be dropped as well. plus money's a little tight after the purchase. how important is it to be on time? I'm no more than an hour or two off, is this a problem? also they are starting to look wilted but have hard dark green leaves what's this all about?

 

Im just a new grower myself but i do know that if you keep doing that your plant will start to flower earley. If that happens your plant will not be sexually mature and it will not grow to its full potental

 

letting it have more than 12 hrs of light after blooming started can make the plant revegg, if not turn into a hermie. Sheesh, a timer will only cost about 10-15 bucks, spend the dough and get one.