Something has been bothering me (in an æsthetic way) for some
time.  When an event scheduled for the day before is displayed in the
default agenda view, it displays the days overdue as "2" which seems
wrong to me.  I wonder if somebody can give me the justification for
this?

The code in question, with my own change to fix this to display "1" day
overdue in such cases, is:

--8<---------------cut here---------------start------------->8---
@@ -6214,7 +6214,7 @@ scheduled items with an hour specification like [h]h:mm."
 		     (pcase-let ((`(,first ,past) org-agenda-scheduled-leaders))
 		       ;; Show a reminder of a past scheduled today.
 		       (if (and todayp pastschedp)
-			   (format past (1+ diff))
+			   (format past diff)
 			 first))
 		     head level category tags time nil habitp))
 		   (face (cond ((and (not habitp) pastschedp)
--8<---------------cut here---------------end--------------->8---

thanks,
eric

-- 
: Eric S Fraga (0xFFFCF67D), Emacs 26.0.50.1, Org release_9.0.5-370-g9f3a02.dirty