Computer expert nails down Jewish New Year

SAN FRANCISCO, Sept. 8 (UPI) -- A San Francisco-based computer scientist says he has solved the mystery of dating Rosh Hashana, the Jewish New Year.

Year 5771 begins at sundown Wednesday.

Steve Morse's interest in the Jewish calendar began when he was a teenager, more than 50 years ago, The Denver Post reported. He tried to figure out his grandmother's birth date in the Gregorian calendar -- the one commonly used in most of the world now -- from the one in the Jewish calendar used on her records from Europe.

The Jewish calendar is a difficult one, based on the movements of the moon and sun. His grandmother was dead by the time he knew her secular birthday, but Morse's interest in the subject continued.

In between designing the Intel 8086 chip and other achievements in computing, Morse designed software to convert Jewish to Gregorian dates, significant for genealogists because many older documents give only Jewish dates.

He also found his software did not work well for determining when Rosh Hashana begins. The Jewish New Year starts on the first day of the month of Tishri.

"The rabbis I asked didn't know about mathematics," Morse said. "My mathematician friends don't know the Jewish calendar."

Finally, Talmudic scholars explained to him that the first Rosh Hashana occurred at the end of a week of creation that ended Year 1 in the Jewish calendar. Morse had assumed Year 1 began with creation.