Hey people!!

This might be a really stupid question but I promise ive searched and searched for the answer but to no success,

My question is how long my plants will still veg when I switch to a 12/12 light cycle? For some reason I've got two weeks in my head but because of the limited grow space I need to know how much they will continue to grow so I can work out how much room I need left when I switch to 12/12!

Thanks for your wisdom in advance lol! and I do apologise if this is seriously a stupid question!!

Dubness