The date 5 years ago today was [current date] - 5 years.
Since today is July 14, 2013, five years ago today it was July 14, 2008.
As today is the 17th of March 2018, then 29 years ago it was the 17th of March 1989.
1913 (2013)
19 years ago today it was Wednesday May 27, 1998.
Five years earlier that the date in question. I leave the simple calculation to the student.
This depends on what today is. See the related link, "100 years ago today". To calculate late the date, subtract 100 from the current year, and use the same date. For example, of today were July 5, 2015, then 100 years ago would be July 5, 1915, since 2015 - 100 = 1915.
Depending on what date you are thinking of, and what date it is today, it would vary a bit, but one could say approximately 3,010 years ago.
To find the date that was 13 weeks ago from today's date, you would subtract 13 weeks from today's date. If today's date is August 12th, 2021, then 13 weeks ago would be May 13th, 2021.
The Nintendo 3DS was released about 4 years ago as of today in 2015.
As today is November 21, the date 46 days ago would have been October 6.
Today's Date - 3.