The Chief Rabbinate decided Monday that celebrations for Jerusalem Day, scheduled to take place next month, will be postponed one day, from Saturday night to Sunday. Jerusalem Day commemorates Israel's regaining control of the entire city of Jerusalem during the Six Day War of 1967.
The rabbinate made its decision to avoid encouraging ceremonies which might violate certain Shabbat prohibitions. The decision does not bind all state institutions and is mostly relevant to private ceremonies and those who observe Shabbat prohibitions.
The rabbinate has made similar decisions in the past regarding ceremonies for other holiday that fall on a Saturday night.