4 weeks flower, one of my lights stuck on during 12 hour dark period

just had a massive problem, although im not sure what kinda damage it will do as i have never come across it before

basically, the 600w lamp in my setup had an enclosed ballast with a plug top on it, so, as a temporary measure, i just plugged it into a socket with one of those timers you get for plugs, until i got it wired in with the rest of the lights on their timer.

so today i went out just before lights on, and noticed they were all off, bar the 600w.

the stinking fucking cheap ass timer must of stuck on

anybody know what kinda damage that would do to me, 1 of the lights staying on during the 12 hours it was supposed to be off ?

have the light wired in with the rest now, really angry about it

It will definitely cause some stress. Return the plants to normal lighting schedule and hope for the best.

thats what i thought, lights are back on schedule now just hope not too much danage done