not quite theres a few ways you can do it but id advise that the time you take off be taken off of a night time.
because that when your lightings going to be getting varied the most anyways.
what im saying is its all ways going to be daylight at 7.30 am really,,, but out of summer/spring its liable to be getting dark earlier anyways and having the uv rays in our atmosphere change earlier and earlier of a night once summers over...
this is what the dark room is supposed to symbolize/mimmic..
your tricking the plant into thinking the seasons have changed and its time to flower...
like i said theres a few ways to do this
but in your case (plants already been thrue a bit and this isanother chang its gotta adapt to and hopefully prosper)
I would slowly reduce the time i brought it in by like 5 mins a day or 20/30 mins every few days a week depending on your sitch... this would only help your case because once it started flowering and you deducted (a little more light time so it wont get stuck in limbo) you wouldnt be depriving it of more light than you have too.. in your case this would be a real good thing..
really what i would have done is similar too what i just said but i would dpo one of a few things....
bring it in a few hours earlier from the first night... just figure out what you reckon should sufice, thats all i do when i do this it works for me... my grow area and climate may be a bit diff to yours and this works for me...
and i know slowly bringing it in earlier on a basis to mke the plant think its seasons changing works where i am.....
but some of our seasons are kinda changing and out a bit so some of the things i used to do are a bit different now.
ie start indoors finish out.. you get a problem with limbo sometimes if you plan it wrong and put them outside during the hottest part of summer
LIMBO= plant goes beetween veg and flower,,, this may mayy cause stress in my experiences..
but anyways you should be thanking this plant really not hating it id say you learnt some good lessons already.... i wouldnt let this discourage you its az lerning curve the whole time all the time if you make it that way...
like i said these plants are as simple or hard as you make them really,
i personally like trying new shit every once and a while

i find it fun..
but as for your questions
umm i dont know what your environments like, so i cant ell you exactly what to do but id reverse it and be bringing it in of a night earlier.
ud keep them for a few days/a week even more if you want remember you dont know how much light you need to deduct where you are, and your new to this..
hours half hourz decreased
if you have 12 hour days you know your not going to be tqaking more than 6 by the end of it (I SHOULD THINK NO WHERE NEAR IT) more than likely 3 by the end of it,
like i said in your case id do 5/10 mins earlier every few days/week (the extra time it veges for cant hurt too much.
but if your intent on half hours id say every week or two.... just remember i think you should be able to get it veging with a loss of close to three hours (maybe less tho if your lucky)
sorry i am finding it hard to explain this. i maself have to earn by practical and teaching myself. This in turn seems to make me a pretty shitty teacher, i do however know what im on about...
i know how to do this fairly well but i preffer to let my plants grow to theyre potential and change at propper times.... once you know how todo hs well an have your dry spills figured... you ca have a plant ready when youd normally have none...
i am trying to take in account of what your plants have been thrue and need best i can and write it down as fast as it comes to my head..... so if i confuse you please point it out.. its your babies life were playing with here...
i think your slowly getting the idea tho......
like i said you should thank your plant shes tought you a lot...
and better to find out now than further down the track if you get bigger ambitions isnt it
