REL: 4.0.0

Author: effigies

Changelog

@@ -25,8 +25,8 @@ Eric Larson (EL), Demian Wassermann, Stephan Gerhard and Ross Markello (RM).
 
 References like "pr/298" refer to github pull request numbers.
 
-4.0.0 (To be determined)
-========================
+4.0.0 (Saturday 18 June 2022)
+=============================
 
 New feature release in the 4.0.x series.