nutrients/lights effect flowering times alot of times i've seen people use potassium in higher amounts with de leafing to send a plant into shock and flower faster, Heavy hps lights also can effect flowering compared to leds, I wouldn't take any flowering time as gospel as even a clone will flower faster/shorter amount of time when put into a different systemI’ve been looking for the northern lights we had from the late 80’s and early 90’s that was completely done by 7 weeks. It was probably an early version of the European reworked version if the original takes 9 weeks.