Help from anyone in the UK or knows about force flowering outdoors!!?

I'm currently growing a plant in a greenhouse in the UK but to flower it I have been taking it inside every night which is a bit annoying. I have bBen doing this for 3 weeks now and I'm wondering if there is enough darkness in the UK at the moment to ensure my plant continues to flower without having to take it inside?? Ideally I would just leave it in the greenhouse the while time. Any ideas??

should have just let it do its thing for the extra 3 weeks, and croped in croptober.....i would keep bringing it inside untill the end of the1st week of sep to be safe. 3days back in veg light and it will want to start reverting (even tough it takes ages to revert properly)

12/12 sunlight/dark starts in September in UK.