Landis disliked the innovation of "night baseball", played in the evening with the aid of artificial light, and sought to discourage teams from it. Despite this, he attended the first successful minor league night game, in Des Moines, Iowa, in 1930. When major league night baseball began in the late 1930s, Landis got the owners to restrict the number of such games. During World War II, many restrictions on night baseball were reduced, with the Washington Senators permitted to play all their home games (except those on Sundays and holidays) at night.