Yom Yerushalayim — Jerusalem Day — is the most recent addition to the Hebrew calendar. It is celebrated on the 28th day of Iyar (six weeks after the Passover seder, one week before the eve of Shavuot). In 2017 Yom Yerushalayim falls on May 24 and begins on the eve of May 23 at sundown.
Although Jerusalem has been considered the capital city of the Jewish people since the time of King David — who conquered it and built it as the seat of his monarchy in approximately 1000 BCE – there has never been a special day in honor of the city until the Israeli army took over the ancient, eastern part of the city on the third day of the Six-Day War in June 1967. On that day the eastern and western sections of Jerusalem were reunited again.