Time-variations of Solar Neutrino Signals

The most popular solutions of the solar neutrino problem which assume massive neutrinos predict varying with time signals in the solar neutrino detectors. The variations represent a distinctive feature of these solutions and do not depend on the theoretically predicted total flux of neutrinos from the Sun. The time scale of the variations ranges between an hour (MSW) and several years (neutrino magnetic moment). The amplitude of the variations depends on the neutrino oscillation parameters. Future detectors with high event rates will be able to test these predictions at a new level of precision. The prospects for testing neutrino physics solutions by these detectors will be discussed and the limits on the neutrino oscillation parameters that one should be able to obtain will be presented.