Special events and other funny days

The holiday is usually celebrated on June 9th, which is depicted numerically as 6/9.

National 69 Day is one of a number of unofficial holidays of unknown origin, but that doesn’t make it any less real or any less … enjoyable … to celebrate. As its name implies, National 69 Day is dedicated to having oral sex.

Second day of Pentecost (Holiday in Norway)

Like the second day of Easter and the second day of Christmas, the second day of Pentecost has no religious significance. Still, it is traditionally a day off.
People often travel away at Pentecost, and therefore Monday in Norway has become a day off.

It can be discussed how comfortable, delicious and hygienic it is to ride naked, but it must be good for the environment.
And that's why there are thousands of people in large parts of the western world stepping forward and throwing away their clothes on June 9th.