Last Quarter Moon

Last night, January 25, at 11:05PM , was moon rise of the Last Quarter of the last month of the current lunar year (based on the Chinese lunar calendar).  Although it was hidden by rain clouds, it peeked for several minutes at 5:45 this morning, January 26.  Luckily I was able to get a few shots through a veil of thin clouds.

With the coming Chinese New Year and my fascination for the moon, it got me doing research on lunar calendars. I’d like to share with you some of what I’ve found out about the lunar calendar:

A lunar month, on the average, is approximately 29.53 days.  Thus, lunar months alternate between 29 and 30 days, called hollow and full months.  Since the lunar month is shorter than a solar month, a lunar year of 12 lunar months of 354 or 355 days (11 to 12 days shorter than a solar calendar).  The lunar year goes back to its original relation to the solar year every 33 lunar years.

The Islamic calendar (called Hijri calendar) is the only purely lunar calendar.  The Hebrews and the Chinese follow a mixture of the lunar and solar calendar (sometimes called lunisolar calendar).  Even if the they have the same base, they do not celebrate the lunar new year on the same date.  For instance, the Chinese New Year in 2010 was celebrated last February 14.  The Hebrew New Year was celebrated last September 9.  The Islamic New Year, Al-Hijira, on the other hand, fell on December 7.

A leap month (or intercalary month) is added to the lunar year every 2 or 3 years to synchronize the lunar year with the solar year (the Hebrew calendar does this to keep Passover in the spring).  The Islamic and Hebrew calendar start the lunar month with the 1st visible waxing crescent (that’s why one of the symbols of Islam is the Crescent Moon).  The Chinese lunar month begins with a new moon.  The Hindu lunar month begins on a full moon.

With all these differences, it seems I’m not alone in going gaga over the moon.