Today in Comics History, April 27, 1986: First Bi-Annual Commemoration of Death of Robin II (Observed)

from Batman Annual (1961 series) #25 (DC, May 2006), script by Judd Winick, pencils by Shane Davis, inks by Mark Morales, colors by Alex Sinclair, letters by Travis Lanham
Yep, Jason Todd died on April 27. And not at all on September 15.