Once in blue moon!
You all must have heard and also used the phrase_ “Once in a blue moon” , but many of us may not know what is a blue moon, or rather when is a blue moon.
If a full moon occurs twice in a calendar month, the second one is known as the blue moon.
A lunar cycle is 28.53 days long. So if a full moon occurs in the very beginning of a month, chances are that there will be another full moon towards the end of that month. But such a phenomenon is rare, hence the phrase “once in a blue moon”.
Just for academic interest, here is the full moon~blue moon calendar …upto the year 2020…
02 July & 31 July 2015
02 January & 31 January 2018
02 March & 31 March 2018
01 October & 31 October 2020
Source :::: input from a friend of mine
Natarajan
Take off with Natarajan 