Extra light

Im in the last couple weeks of flowering, have been on 12/12 for about 50 something days, i have my timer from 7pm to 7am, however today the light went till 9am, and gave my plant 2 extra hours of light, whats gonna happen, im using a 400Watt HPS

one time won't do anything.

Nothing will happen, absolutely nothing. Just put it back to 12/12 and it will be fine.

OR it will grow a big, deformed, hairy cock and balls and fill your growroom with semen, but that's highly unlikely.

As long as the dark period is longer than 12 hours they will probably be ok