More than 50,000 people have taken part in the Birkat Hahama prayers at Jerusalem's Western Wall.
The event, a blessing of thanks for the world's creation, occurs when the sun reaches the same spot in the firmament as when it was created, according to the Talmud. It will not occur again for 28 years.
Thousands gathered in large groups throughout Israel and the event was marked in many time zones, starting with members of the small Jewish community in New Zealand. In hundreds of places all over the world, observant Jews rose before dawn for outdoor prayers and dancing.