Thats debatable. Flowering actually starts the day the light cycle is changed to a flowering photoperiod, correct? ok so you can start counting the weeks when you change to a flowering photoperiod. I guess a few growers might not count the first week but they probably dont use the dark period technique so their plant probably are slow a week. More than likely when you use the 36hr dark period, by the end of their first week 12/12 they already have budsites forming.
SD you did half and half right? so, you will see which plants show budsites sooner and decide if you want to count the first week. I always do. later yall, got class till 9:30