Saturday.
The day of the week April 18,2007 occured was on Thursday.
November 18 1978 was a Saturday.
March 18 1949 was a Friday.
March 18 1971 was a Thursday.
September 18, 1947 fell on a Thursday.
June 18, 1947 was a Wednesday.
It was a Friday.
It was a Saturday.
July 18th, 1947, was a Friday.
April 18 1947 was a Friday.
September 18 1961 was a Monday.
September 18 2010 was a Saturday.
August 18th, 1947 fell on a Monday.
September 18, 2012 was a Tuesday.
September 18, 1977 fell on a Sunday.
September 18, 1957 fell on a Wednesday.