History around The National Foundation Day
Japan's first official history book "Nihon Shoki" which was written in 720 said that February 11th was the day that Jinmu the first Emperor of Japan ascended the throne in 660BC.
"Emperor Jimmu" Artist: Tsukioka Yoshitoshi (1839-1892)
However, it wasn't true history. Almost all of modern studiers of Japanese history think that the oldest existing emperor was in the 3rd century. However, from the 1870s to 1945, the Japanese government had told citizens that it was true history, because the dignity of the old Emperor system was needed to rule Japan smoothly. In 1872, the 11th of February was set as "the National Foundation Day." The government enhanced the dignity of the Emperor by, for instance, educating citizens that the Emperor was the descendant of gods. Using this entitlement, the government began to say that Japan, the nation of the gods, should rule Asia.
Abolition and revival
After WWII, the US occupation army banned the political usage of the Emperor. In 1946, the Emperor Hirohito (the period of his reign: 1925-1989) declared as follows: The tie between citizen of Japan and the Emperor doesn't depend on unreal thoughts, such as, "The emperor is the living god" and "The Japanese race is more excellent than other races, therefore the Japanese race should rule the world."
In 1948, The National Foundation Day was abolished.
As time passed, some diet members of the administration party (the Liberal Democratic Party which it is conservative, and does not live up to the name) submitted the bill of the National Foundation Day. The members of left sided parties were strongly against them. In 1963, when a member of the LDP tried a forcible passage of the bill, opponents tackled him and this LDP man was carried to a hospital.
After that, the LDP members proposed an alternative plan to opponents. "How about we change the name of the February 11th holiday from The National Foundation Day, to The Day for the National Foundation," they said. "This name doesn't mean that the national foundation occurred on the 11th of February. People can think that this day is for thinking of and respecting the nation." In 1966, opponents compromised to this idea. Since 1967, the 11th of February in Japan has been made a the holiday again.
The communist party reacted with slight resistance. The party didn't admit the day as a holiday, therefore members and staff of the party worked on the 11th of February. Some people felt it was a proud act. but some other people didn't like it. For example, children of the staff hated the system because they weren't able to go on vacation on the day like other non-communist families. In 2004, the party began to treat some "controversial" days as holidays -- the 11th of February, the 29th of April (Showa Emperor's birthday, in 2004, it was called "Greenery Day", but now has reverted back to "Showa Day") and the 23rd of December (the reigning Emperor's birthday)
I also don't think the 11th of February as the real national foundation day. On the other hand, I think that the existence of the Day for National Foundation is good. Another date is better, however I can't conceive of a more proper date. The 3rd of May, the day the present Constitution came into effect in 1947 may be the best, but the day is already established as the Constitution Memorial Day, a national holiday.
The 11th of February is the Day for National Foundation - it is not proper, but I reluctantly admit it.