Time-of-night variation of solar neutrinos

We investigate the time-of-night variation of solar neutrino rate which will be of relevance to Super-Kamioka and Sudbury neutrino detectors in the framework of oscillations among the three flavors. An analytical method of computing the regeneration in the earth is presented. If day-night effect is seen, we show how the study of the time-of-night variation will allow the determination of the neutrino parameters.