During the 1908 Olympics in London, the Russians showed up 12 days late since they were using the Julian calendar instead of the Gregorian calendar.
Here is the crux of the controversy: until 1918 Russia lived according to the (Old) Julian calendar, which lagged two weeks behind the modern Gregorian calendar in use in Europe and North America. Many experts put it this way: Russia’s national team arrived in London two weeks later and missed some of the competitions; luckily enough, the Russians still had 4.5 months ahead of them.
“The Russian national team forgot that Great Britain had switched to the Gregorian calendar 200 years prior… When the Russian delegation started to sign up, it turned out that the Olympics were already very much on, and some competitions had already ended,” wrote the Russian news portal, Lenta.ru.
Sports Illustrated describes the incident as follows, concentrating on the shooting competition that the Russians missed: “On July 11, 1908, the U.S. edged out Great Britain to take gold in the event. The Russians didn’t appear on the standings and were non-competitive. Not because they weren’t any good, but rather because they weren’t present. While they arrived in town a few days before July 11, they did so according to the wrong calendar.”