For many people, and in many societies, the start of a new year is a festive, joyous occasion. But most of us regard New Year’s Day (January 1) as a purely secular holiday, with little or no real religious meaning.

Other cultures, however, often follow entirely different calendars of their own. And in some other cultures, the coming of the new year is an occasion of deep religious meaning, and of profound spiritual significance.

Today, according to our secular Western (Gregorian) calendar, is September 17, 2012. For most of us, that’s just another day.

However, according to the traditional Jewish calendar, today is the first day of the month of Tishrei. And the first two days of the month of Tishrei are, for Judaism, very special and religiously significant days indeed.

Jews worldwide are today celebrating Rosh Hashanah (Hebrew for “Head of the Year”), otherwise known as the Jewish New Year. In addition to marking the start of a fresh new year on the Jewish calendar, this major Jewish holiday also commemorates God’s creation of the universe and of human beings.

It also serves as the first day of a ten-day period known as the High Holy Days, or the Days of Awe, a time for solemn introspection, thoughtful reflection, self-assessment, and repentance for wrongs committed during the previous year. These traditional Ten Days of Repentance will culminate with Judaism’s holiest of holy days, Yom Kippur (the Day of Atonement).

Since Judaism reckons a day as beginning not at 12:00 midnight but instead at sunset, Rosh Hashanah technically began at sunset last night (on September 16). It is generally observed for two full days, which means that Rosh Hashanah will conclude at sunset tomorrow night (September 18).

Rosh Hashanah always falls on the first and second days of the month of Tishrei; however, those fixed dates on the Jewish calendar do not always coincide with September 16 – 18 on the Western (Gregorian) calendar.

The Jewish lunar calendar counts and calculates its lunar months quite differently, such that there is a certain amount of drift from year to year, relative to the widely-used Gregorian calendar. Last year (2011), for instance, Rosh Hashanah (1 – 2 Tishrei) fell upon September 28 – 30; next year (2013), it will occur September 4 – 6.

Allow me now to take this opportunity to wish my Jewish readers around the globe L’Shana Tova! (Hebrew for “For A Good Year,” a traditional Rosh Hashanah greeting)