By calculation (generator: ["day_week@trueknowledge.com"]) I know that:
Wednesday
is the day of the week of
April 9th 1980
Thursday
is the day of the week of
April 9th 1981
Friday
is the day of the week of
April 9th 1982
Saturday
is the day of the week of
April 9th 1983
Monday
is the day of the week of
April 9th 1984
Tuesday
is the day of the week of
April 9th 1985
Wednesday
is the day of the week of
April 9th 1986
Thursday
is the day of the week of
April 9th 1987
Saturday
is the day of the week of
April 9th 1988
By calculation (generator: ["timepoint_when_day_happened_on@trueknowledge.com"]) I know that:
April 9th 1980
is a timepoint when the day happened on
Wednesday, the 9th of April and 1980s
April 9th 1986
is a timepoint when the day happened on
Wednesday, the 9th of April and 1980s