Our New York Times Recession/Depression Index goes back to 1851 (found here). Is it any good? It is fairly reliable in indicating the end of the recession.
Below is the monthly New York Times Recession/Depression Index from January 2000 to April 2020.
The April 2020 numbers are only estimates. However, three days into the month and April is setting up to exceed the 2000 to 2002 period.
see also: August 2009: The Recession is Over