Going from the beginning of the 20th century to 2014, it was on a Saturday in:
1901
1907
1912
1918
1929
1935
1940
1946
1957
1963
1968
1974
1985
1991
1996
2002
2013
April 20, last fell on a Saturday in 2002 and will again fall on a Saturday in 2013.
April 20, last fell on a Saturday in 2002 and will again fall on a Saturday in 2013.
The 20th of April 1963 was a Saturday.
April 20th 1968 was a Saturday.
Twice, in the US. August 20 will fall on a Saturday in the year 2011 and 2016.
Easter was on April 20 in 1930 and 2003. It will be on April 20 again in 2014.
20 April 1957 was a Saturday.
April 20, 1935 was a Saturday.
April 20, 1912 fell on a Saturday.
For any given date (such as April 20), one out of every seven years it will fall on any given day of the week - at least, that's what happens in the long-term average.
Saturday
saturday