MSU Horticultural Extension Light duration greatly influences plants, as flowering and rest periods are triggered by particular daylengths. Actually it is the length of the dark period, or night, that controls the response.
Duration can partially compensate for low light intensity.
Plants growing in low light may be more tolerant, if the duration of the light is longer. This is often done with artificial lighting. However, plants generally do not do well in continuous light. Altering the daylength may disrupt the blooming cycle of flowering plants, or, it may be used to bring them into bloom at a particular time. A plant may tolerate low light intensity but this does not mean it requires it.