diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index 069a853bdd..81564664eb 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -1,4 +1,4 @@
-*diff.txt*      For Vim version 9.1.  Last change: 2024 Mar 28
+*diff.txt*      For Vim version 9.1.  Last change: 2025 Mar 28
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar