diff --git a/ietf/templates/doc/draft/issue_working_group_last_call.html b/ietf/templates/doc/draft/issue_working_group_last_call.html
index 412830edc7..d6f35a0e82 100644
--- a/ietf/templates/doc/draft/issue_working_group_last_call.html
+++ b/ietf/templates/doc/draft/issue_working_group_last_call.html
@@ -21,10 +21,41 @@ <h1>
     <form class="mt-5" method="post">
         {% csrf_token %}
         {% bootstrap_form form %}
+        <div id="end_date_warn" class="alert alert-warning d-none" role="alert">
+            All dates have been updated automatically in the Subject and Body fields with the End date value. Since you previously edited these fields manually, review both to ensure they match your expectations.
+        </div>
         <button type="submit" class="btn btn-primary">Submit</button>
         <a class="btn btn-secondary float-end" href="{{ doc.get_absolute_url }}">Back</a>
     </form>
 {% endblock %}
 {% block js %}
     <script src="{% static 'ietf/js/datepicker.js' %}"></script>
+    <script>
+        (function () {
+            const datepickerElm = document.querySelector('#id_end_date')
+            const subjectElm = document.querySelector('#id_subject')
+            const contentElm = document.querySelector('#id_body')
+            const warnElm = document.querySelector('#end_date_warn')
+            let isSubjectOrContentDirty = false
+
+            // Handle date auto-replace in subject + content
+            datepickerElm.addEventListener('changeDate', ev => {
+                subjectElm.value = subjectElm.value.replaceAll(/2[0-9]{3}-[0-9]{2}-[0-9]{2}/g, datepickerElm.value)
+                contentElm.value = contentElm.value.replaceAll(/2[0-9]{3}-[0-9]{2}-[0-9]{2}/g, datepickerElm.value)
+
+                // Warn about auto-replace on dirtied fields
+                if (isSubjectOrContentDirty) {
+                    warnElm.classList.remove('d-none')
+                }
+            })
+
+            // Detect dirtied fields
+            subjectElm.addEventListener('input', () => {
+                isSubjectOrContentDirty = true
+            })
+            contentElm.addEventListener('input', () => {
+                isSubjectOrContentDirty = true
+            })
+        })()
+    </script>
 {% endblock %}
\ No newline at end of file