[Gardeneer]

In the US DTM means from tranplant ( seedling of about 8 inch tall).
To me it is a rough ball park number. The same variety in different growing conditions/climate may have baried DTM. In cool PNW for emple it will take much longer than in the south like Alabama
From Seed to Ripe Fruit add about 45 days. So if a variety os listed as with DTM =75 , it will take about 120 days from sowing seeds.