How do tomatoes know they've been transplanted?

When you buy tomato starts from the store, each variety has a "days to maturity" on the tag. With Day 1 being the day you plant it in the garden. How do tomatoes know they've been transplanted?

What if I grew some tomato starts and kept uppotting them for like three months after sowing, obviously it wouldn't take them, say, another 90 days to reach maturity, right? So what's the difference here?