Obon is one of the most important Japanese traditions. People believe that their ancestors` spirits come back to their homes to be reunited with their family during Obon and pray for the spirits. For the reason, Obon is an important family gathering time, and many people return to their hometowns. Obon was originally celebrated around the 15th day of the seventh month in the lunar calendar. Obon periods are nowadays different in various regions of Japan. In most regions, Obon is celebrated around August 15, and it typically begins 13th and ends 16th of August. In some areas in Tokyo, Obon is celebrated around July 15, and it is still celebrated on the 15th day of the seventh month in the lunar calendar in many areas in Okinawa. Japanese people clean their houses and place a variety of food offerings such as vegetables and fruits to the spirits of ancestors in front of a butsudan (Buddhist altar). Chochin lanterns and arrangements of flower are usually placed by the butsudan.