World Architecture Day is celebrated on the first Monday of October. This year  it is celebrated on October 7. In 1946 there was an international conference of architects in London. During the conference   it was decided to found a  new organization, which was called International Union of Architects (UIA). Nowadays International Union of Architects has more than one hundred sections in different countries. More than one million architects are the members of the Union. In 1985 during the conference of International Union of Architects it was decided to celebrate World Architecture Day on the first day of July, then in 1966 in the 20th summit of International Union of Architects held in Barcelona, it was decided to celebrate the day on the first Monday of October.