One difference at night is that it is cooler, so less water may be lost when the stomata are opened for gas exchange. Many plants (separately) evolved a photosynthesis cycle where gases need only be exchanged at night and the stomata may be closed during the day.[1] While the actual photosynthesis reaction happens during the day, the nighttime preparation is needed, and should perhaps be counted towards the effort.

https://en.m.wikipedia.org/wiki/Crassulacean_acid_metabolism