Monday.
June 18 1970 was a Thursday.
April 18 1970 was a Saturday.
October 18, 1970 was a Sunday.
September 18, 1970 fell on a Friday.
February 18, 1970 is a Wednesday.
That was a Friday.
It was a Wednesday.
August 18, 1970 fell on a Tuesday.
18 May 1962 was a Friday.
May 18 1933 was a Thursday.
May 18 2010 was a Tuesday.
May 18, 2009 was a Monday.