Update ChangeLog for 4.1.0.
diff --git a/ChangeLog b/ChangeLog
index e35d74c..9cbfbf9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,7 +4,7 @@
 
     https://github.com/jemalloc/jemalloc
 
-* 4.1.0 (XXX)
+* 4.1.0 (February 28, 2016)
 
   This release is primarily about optimizations, but it also incorporates a lot
   of portability-motivated refactoring and enhancements.  Many people worked on