diff --git a/lisp/org-agenda.el b/lisp/org-agenda.el
index 57cddcfe9..0f61d75bb 100644
--- a/lisp/org-agenda.el
+++ b/lisp/org-agenda.el
@@ -6335,6 +6335,11 @@ specification like [h]h:mm."
     (org-element-cache-map
      (lambda (el)
        (when (and (org-element-property :deadline el)
+                  ;; Only consider active timestamp values.
+                  (memq (org-element-property
+                         :type
+                         (org-element-property :deadline el))
+                        '(diary active active-range))
                   (or (not with-hour)
                       (org-element-property
                        :hour-start
@@ -6536,6 +6541,11 @@ scheduled items with an hour specification like [h]h:mm."
     (org-element-cache-map
      (lambda (el)
        (when (and (org-element-property :scheduled el)
+                  ;; Only consider active timestamp values.
+                  (memq (org-element-property
+                         :type
+                         (org-element-property :scheduled el))
+                        '(diary active active-range))
                   (or (not with-hour)
                       (org-element-property
                        :hour-start