This year, the month of October will aptly describe the phrase ‘Once in a Blue Moon’. This is due to the fact that on Saturday, there will be a rare incidence of a second full moon known as ‘Blue Moon’. Usually, every month witnesses one full moon and a new moon. Nevertheless, there are some rare occurrences when the same month gets two full moons. This month on October 1, there was a full moon and the next full moon can be seen on October 31. In a calendar month, when there are two full moons, the second moon is termed the Blue Moon. Lunar month is of a duration of 29.531 days or 29 days, 12 hours, 44 minutes, and 38 seconds.
So, the first full moon should take place on 1st or 2nd of the month, to have two full moons in a month. Over the months, this extra time accumulates. There is one extra full month in the year after almost 30 months. In February, it is impossible to have a full moon as it has only 28 or 29 days (in a leap year). To have a Blue Moon in a month of 30 days, is quite uncommon. June 30, 2007 was the last Blue Moon in a month with 30 days and next is slated to be on September 30, 2050. In 2018, there were two Blue Moons, the first one on January 31 while the second one on March 31.
This rare event took place because the earlier month had only 28 days. On August 31, 2023, the next Blue Moon will take place. This phenomenon is mostly limited to the Gregorian calendar used globally. This is why we get to hear phrase ‘Once in a Blue Moon’, signifying something which does not take place very often.
Courtesy: Financial Express