Generally from planting out. In the case of tomatoes planting out is typically assumed to be when 50% of the plants have the first flower open. However, Tim,you've missed a word. It should be relative days to maturity. The relativity is between different cvs. of the same vegetable and is not absolute days to maturity. Nor it dependent upon indoor or out, given that most cvs. are deemed most suitable for one or the other, not both, and it is assumed they will be grown accordingly.