decoded-time-add doc string addition

* lisp/calendar/time-date.el (decoded-time-add): Add a usage example.

diff --git a/lisp/calendar/time-date.el b/lisp/calendar/time-date.el
index 0aa38166bc1343b58f04037745c195914a946f54..155c34927fd714e8fc4f2398a387517334052772 100644 (file)
--- a/lisp/calendar/time-date.el
+++ b/lisp/calendar/time-date.el
@@ -406,7 +406,11 @@ entries only for the values that should be altered.
 
 For instance, if you want to \"add two months\" to TIME, then
 leave all other fields but the month field in DELTA nil, and make
-the month field 2.  The values in DELTA can be negative.
+the month field 2.  For instance:
+
+  (decoded-time-add (decode-time) (make-decoded-time :month 2))
+
+The values in DELTA can be negative.
 
 If applying a month/year delta leaves the time spec invalid, it
 is decreased to be valid (\"add one month\" to January 31st 2019