diff --git a/functions/datetime.xml b/functions/datetime.xml
index fedf1b41f5..a907def3d5 100644
--- a/functions/datetime.xml
+++ b/functions/datetime.xml
@@ -654,6 +654,14 @@ echo strftime ("Last day in Feb 2000 is: %d", $lastday);
week
+
+
+ %V - The ISO 8601:1988 week number of the current year as a
+ decimal number, range 01 to 53, where week 1 is the first
+ week that has at least 4 days in the current year, and with
+ Monday as the first day of the week.
+
+
%W - week number of the current year as a decimal number,