Seed sellers eta?

[2wasted]

I used to do autoflower and found i never got them to "peek" @ amber/brown colored, but then i was using cheap LED's, so bought a quality samsung led light and went back to normal fem seeds,so my question is likely going to sound stupid as i have been doing this awhile(slow learner :P ), but is the eta given is for everything under perfect conditions ? so using that rationale is 10 or more percent usual/expected in a grow? do u use it as a guide or ignore it?

[Valentina]

Mine has blurple osram chips and have got my autos to amber in the time frame povided by the seed breeder.

Good luck with the Samsungs