What are the different beliefs of the number 13?
It was suggested by Charles A. Platt writing in 1925 that the reason 13 is considered unlucky is that a person can count from 1-12 with their 8 fingers, two thumbs and 2 feet, but not beyond that, so the number 13 is unknown, hence frightening, hence unlucky. This idea discounts the use of toes or other body parts in counting.
According to another interpretation, the number 13 is unlucky because it is the number of full moons in a contemporary year, but two full moons in a single calendar month (mistakenly referred to as a blue moon in a magazine article of the 1940s) only happens about every 2.5 years. Early nursery rhymes stated there were thirteen months in a year ...more
for ur information , some time the loop it from nwxt no. in some hotels 13 no room is not available, 13 th table is diapperred.
on the 13sep( i am not sure abt month) they r so feriously past that day.