Vodka Day is celebrated annually on the 4th of October.
Mind you, for some people, Vodka Day comes more than once a year — and they know by 9 in the morning whether it’s going to be a Vodka Day or not.
On the 4th of October in 1582, the great Gregorian calendar adjustment took place in most of Europe. Today was Thursday, 4 October 1582, which happened normally enough. But there was no tomorrow — no Friday, 5 October 1582. Instead, the next day was deemed to be Friday, 15 October 1582 — 11 calendar days later. This was to correct the calendar, which had fallen 11 days behind. The correction did not happen in Britain, America, etc, until nearly 200 years later, in September 1752, and in Russia, at the end of 1918.
With all the confusion, and confusion around the confusion, small wonder perhaps why today got designated Vodka Day.