Tuesday
December 13 1999 was on a Monday.
March 13 1999 was a Saturday.
On January 13 1999 it was a Wednesday
13 July 1989 was a Thursday.
13 July 1970 was a Monday.
13 July 1957 was a Saturday.
13 July 1995 was a Thursday.
July 13, 1956 was on a Friday.
July 13 1963 was a Saturday.
July 13 1949 was on a Wednesday.
July 13 1947 was on a Sunday.
July 13 1978 was a Thursday.