no. DLI is simply how many photons per 24-hour cycle. They are counted in moles. If curious, look up "Avogadro's number" for exact definition of a "mole"
1 mole = 6.023*10^23 ... of photons, molecules, etc. it's origins are more about chemistry, therefore photons are also broken down into this increment to understand interaction with molecules as opposed to per gram. "per gram" is an unsophisticated, unresolved metric for such things. It is severely lacking.
There is variation in how much you can provide... some of it is genetics, but as far as what you control it is your environmental variables, specifically temperature, relative humidity and atmospheric CO2. If these don't jive with how much DLI you provide, negative things can happen... too much will damage the plant, too little will cause excess stretching. There is no target value that is a one-size-fits all.
In the end, you cannot just shoot for a specific DLI. you must always observe and adjust based on the plant's behaviour. DLI is a useful tool and not an absolute value to target.
DLI, once calculated, does cares not for hours of operation, as that is already part of the calculation. DLI allows apples to apples comparison of light applied regardless of area of coverage or hours of operation. 35 moles of photons per day is 35 moles of photons per day whether over 12 hours or 24 and whether covering 50m^2 or 1m^2. Consult any DLI tabele for reference. you need PPFD and hours of operation.
PPFD - people very often don't really know what this means, either. This is umol/s of PAR per meter-squared. IT is phonton per second relative to an area, thefore you can compare different sized areas with this value and it makes sense. 900 PPFD for 2m^2 and 900 PPFD for 1m^2 is providing same rate of photons across the entire area. There are just 2x as many per second in the area that is 2x the size, obviously. That alone is fairly useless information. PPFD and hours of operation can be used to calculate DLI. DLI is what matters.
PAR - photosynthetically active radiation. Also, read up on "ePar". Turns out a slgihtly wider range of wavelengths are causal to photosynthesis than previously thought.
1 single-location measurement of umol/s of PAR is PPE or PPF. This is totally different from PPFD.