Do you count your days since it was sowed?
I click start on my app as soon as they touch moisture. Everything else had too much "grey" to it in my opinion. If the seed will sit dormant for years dry but then signs of life hours after touching moisture makes sense to just start the clock at the event.
I think the days from sprout thing comes from the companies trying to advertise short time-to-harvest, but I'm a big xfiles fan.....