How much will this fuck up my plants?

Ok, just a little background...
6 plants (in soil) under 600w hps (was under 600w mh for veg)
Starting the 3rd week of flower

Arjuns Strawberry Haze x 3
Chronic x 2
Lifesaver x 1

Due to unforeseen circumstances we have to totally change the lighting pattern which is currently 6.30pm (lights on) - 6.30am (lights off)...we need to be something like going on at 6.30am and turning off at 6.30pm

What can i do? What is more important during flower? 12 hours of darkness or 12 hours of light?

Does the plant need the full 12 hours of darkness? I think i read somewhere that it takes 12 hours of darkness for a chemical buildup in the plant?

Can i give it say 12 hrs of darkness and 8 hours of light? Just for the next few days till the pattern gets sorted out?

Sorry for all the questions...this needs to be changed today intime for Monday morning (starting work).

a few weeks ago when i had just switched to flower i had to change the light cycle on my baby 'Deschanel' too. She's unknown strain but smells skunky and looks like a mainly indica cross. from 12/12 i started giving her 14 hours dark and 12 hours light until the light times were at what i needed. then stuck her back to 12/12 again. didn't do her any harm at all, i think it might've kick-started her flowering a little bit too.

if you think about it nature wise the plant starts to bud when the days get shorter and the nights longer - it realises the autumn/winter are coming and wants to make reproduce to keep the species going next year. so in my opinion (which is by no means expert) it'd be less stressful for the plant to have a few hours less light than a few hours more, but you may want to wait for some guru opinions just to be sure

give an extra 12hrs of dark for one day and youll have swapped the on/off times.

ruderalis88, thanks for the reply. a few other people have said the same thing as you...i cant bring down the dark period. i was thinking about 12 hours dark 8 hours light...its only 20 hours but come thur it will have swapped over. then back to 12/12/

But what paddy510 is saying sounds waayy easier.

which method would stress the plant more? dont want them to go all hermy on me.

go with paddy's idea. Don't worry about stressing the plant, 12 extra hours of darkness won't hurt it. If it did, growing outdoors would be impossible.

yeah i've heard that a lot of people boost into the flowering stage with a 24hr dark period, can't hurt them that much! good luck bro

cool thanks for all the advice here folks...think i will go with the 24 hr dark period...i hope this doesnt fuck up....will be totally gutted.

it will be weird not checking on them haha...i have become a little obssesed by them recently. i purchased a green bulb...but it doesnt look right...dont think i will bother using it.

lights back on...will need to keep checking for any signs of uncle herms...but all seems well. pheew

You should be fine....I would have worked my way into the time by adjusting it a few hours each day but you still have a good month or so of growing left

Keep us posted

thats what i was planning on doing boneman, as it would mean more light for the plants instead of 24hr dark period...i couldnt wait till Thurs (thats when they would have swapped over). I will remember this for next time tho...plan it out a little better.

im growing
Arjuns Strawberry Haze x 3
Chronic x 2
Lifesaver x 1

i read that the haze and chronic has like a 9-12 week flowering...im using bigbug which...i hope will speed things up.

you ALWAYS want to go with longer dark periods when adjusting your light schedule...ALWAYS ALWAYS ALWAYS.

well it seemed to go ok...no problems that i could see. just lots of fluffy white hairs on all the bud sites. yay!

started its 3rd week...cant say the buds look massive or anything. but i have been looking at lots of grow journals and noitced they really start packing it on weeks 5+