Do not confuse Day Light Integral with Critical Day Length. DLI is just a measurement of how much photosynthetic radiation falls upon a given area. It is usually measured in Moles per meter square per day. Depending on a number of variables (IE: Geographical location, weather conditions, season, and time day) DLI can be as high as 60 outdoors and 30 in green houses.
As it has been stated before in this thread and
another thread.. Long day / short night plants like a tomato need longer days to flower. Short day / long night plants like cannabis need long nights to flower. The longer nights give cannabis and other "Short day plants" more time to produce flower clusters.