ZMAN Switch

The ZMAN Switch is a patented specialized timer marketed to observant Jewish households and manufactured by ZMAN Technologies of New Jersey, whose inventors are Yonason Bloch and Herbert Klein. Unlike an ordinary mechanical or digital timer, it carries a pre-programmed Jewish calendar running through the year 2050, so that its owner never has to manually readjust it for the changing time of sunset or for the dates of Jewish holidays across the year. It exists to help Jewish households observe the prohibition on operating electrical switches during Shabbat, the Jewish Sabbath that runs from Friday evening to Saturday evening, and during other Jewish holidays, by allowing lights and appliances to be pre-set to turn on and off automatically at the correct times without anyone touching a switch.