What is considered day 1 of flower?

[Mcjoint]

I just flipped to flower about 2 days ago and today I woke up to the tiniest little hairs on two different places. Can I consider this day one or do I still got a little bit to go?

 

[Weaselcracker]

If there's a set standard for when flowering is officially started- I don't know what it is. With cloned plants I just call it day one when I flip to 12/12. From seed I do the same if it looks like they're changing to flowering mode after the flip. Usually the process takes a couple weeks till there are small buds forming. (Sometimes I've flipped too early and they continue to veg for a week or two first). In the end it makes no difference because they finish when they finish- or when you finish them. It's just a reference point.

 

[Vestrimatrik]

It probable should be considered the day you switch to 12/12 but I also keep the day I finish my 1 week flush in the back of my mind. I do this because it keeps my excitement at bay. If you consider counting after a week of 12/12 on a 9 week strain then according to the first day of 12/12 it would be 10 weeks along. Either way I'd let them go the extra length just to be sure.

 

[Obi Wan]

I was pondering this the other day. Here is how I roll:

I start counting flower (from seed) 10 to 14 days after the flip to 12/12.

I also continue veg nutes for those 10 to 14 days of transition.

Additionally I always plan for a 12 week flower. Some may go shorter some may go longer. 10 to 14 weeks of flower is not an unreasonable expectation for many photo period plants.

Bottom line is the numbers are only a guide. Nature does as nature wants. Get a scope and read the trichomes to determine their maturity and when to harvest

Cheers,
/Obi