How early can I harvest early season tomatoes?

I was super happy if I got anything in July.......some folks managed to get some near July 4th but they went thru major efforts to get there. Prewarming the soil, WallsofWater, etc. I never tried container and then moving it outside......didn't have the facilities to hold big pots indoors.

What the seed packet doesn't tell you is that the days to maturity is from when the plants are set out in the garden and that it takes perfect growing conditions for them to make tomatoes in the time stated. I had growing conditions probably similar to yours in western Montana (on the border of zone 4 and 5) and couldn't grow anything other than the early tomatoes. A forty five or fifty day tomato plant still had to be protected from frost both spring and fall. You can add ten or fifteen days to what ever the packet says.

Through the years I have worked with many so called early tomatoes, some say 45 days till harvest. Now these are plants that have been started indoors, and the time is from date of planting outside.

In very good growing weather, I have yet to see any actual 45 day harvest, in fact, even 60 days is rare with these 45 day plants.

I wouldn't invest much in other peoples' experiences. Plants are not uniform in their timing even within the same bed, much less the same zone.

Unless you're growing Brandywines or a related variety, your guide is when the shoulders shift from green. It's not poetic or interesting, but that's how it is.

probably july 15th.