Happy New Year 5770!

To many, the date seems either way late or considerably early, and the four-digit number doesn't jive with the 2009 calendar year.

But in Judaism worldwide, year 5770 of the Hebrew calendar began at sundown Friday.

It's just one of a number of date and calendar differences being noted this week by observant Jews, ranging from the beginning of a new calendar year to the new-year commemoration of what is a holy religious period rather than a secular celebration of parties and fireworks.

"This time of year is the time when interest in the Jewish faith peaks," said Rabbi Benny Zippel of the Chabad Lubavitch of Utah.

The Jewish New Year is called "Rosh Hashanah" — Hebrew for "head of the year." The Torah mandates that the new year begins on 1 Tishrei, the first day of the seventh month of the Hebrew calendar. The first 10 days of the month of Tishrei are called "the Days of Awe," leading to the 10th day of Yom Kippur, or "Day of Atonement."

"Rosh Hashanah is the most auspicious time for a Jew to return to one's faith," said Zippel, noting the 10 days are a period of personal introspection and a time for asking for — and granting — forgiveness.

Rosh Hashanah activities include praying in the synagogue, refraining from work, eating festive meals with the challah bread, enjoying other symbolic foods such as apples dipped in honey and hearing the shofar, the blowing of a trumpet made from a ram's horn.

The holiday can be commemorated over a two-day period, especially when 1 Tishrei falls on the seventh day of the week — Shabbat, or Sabbath — as it does this year.

"The shofar is the highlight of the [Rosh Hashanah] service," RabbiZippel said, "and the intensity and the awesomeness of the Shabbat itself supersedes and transcends the blowing of the shofar that day."

While Rosh Hashanah, Yom Kippur and other Jewish holidays fall on different dates each calendar year, they don't change dates on the Hebrew calendar.

That's because of the different formats of the Gregorian calendar of the Western world and the Hebrew calendar of the Jews — the former being a solar-based calendar and the later a lunar one.

Actually, the Hebrew calendar coincides with three astronomical phenomena — a day's period being one complete rotation of the Earth on its axis, a month being the rotation of the moon about the Earth (on average 29½ days) and the revolution of the Earth about the sun (365 1/4 days or 12.4 lunar months).