lighting question need help asap please!!

would it be better if i went 24 hrs dark before flower from 18/6 or 30 hrs light before they go dark for 12 , for the time frame i want them on and off ? i could use the help asap thank you.

No need to do any of that. Just switch from your Photoperiod (18-24hrs light) to 12/12.. No need to do anything else. Now I would suggest leaving it in darkness for up to 48 hours before harvest but that is to increase resin production..

It's said that if you give them 24 hours of darkness before you flip them, it will kick them into flower sooner. I don't know; you read all kinds of crap on here, most of it nonsense.

ok so bad idea to just leave them on until morning , the reason i ask is i have one room for veg/flower they r 60 days old ,lights go off at 11 tonight want to run them from 11pm to 11am for heat issues , i use one ballast for 400w mh and then a 360w hps just changed the bulb about ten minutes ago. have two 90w led ufos as well