Maybe you've heard that the 2020 Olympics will be in Tokyo? Living in Japan, I hear about it all the time. I guess I didn't pay a lot of attention to what goes into the planning of the big event in years past because I wasn't close to it.
One of the big things about this Olympics is the summer heat. For awhile, daylight savings time during the event was considered. The idea was eventually rejected, as it should have been.
Another issue is the traffic and congestion in Tokyo during the event, as well as immediately before and after when important people will be moving around. The Japanese government has enacted a law to move national holidays from days outside of the time of the Olympics to other days to ease traffic congestion and provide for security.
Anyway, under the new law, Marine Day, which is normally the third Monday in July, will be moved to July 23rd, the day before the Olympic Games begin. Sports Day, normally the second Monday in October, will be moved to July 24th, the day of the opening ceremonies. Mountain Day, normally observed August 11th, will move to August 10th, the day after the closing ceremonies.