diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/js-patron-get-age.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/js-patron-get-age.inc
new file mode 100644
index 0000000000..c4ab0c0cab
--- /dev/null
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/js-patron-get-age.inc
@@ -0,0 +1,20 @@
+<!-- js-patron-get-age.inc -->
+<script>
+    (function() {
+
+        window.$get_age = function(dob, options) {
+            if(!dob) return '';
+
+            var today = new Date();
+            dob = new Date(dob);
+            var age = today.getFullYear() - dob.getFullYear();
+            var m = today.getMonth() - dob.getMonth();
+            if (m < 0 || (m === 0 && today.getDate() < dob.getDate())) {
+                age--;
+            }
+            return age;
+        }
+
+    })();
+</script>
+<!-- / js-patron-get-age.inc -->