diff --git a/reference/datetime/functions/strtotime.xml b/reference/datetime/functions/strtotime.xml
index 3326958660..1fb0a6e991 100644
--- a/reference/datetime/functions/strtotime.xml
+++ b/reference/datetime/functions/strtotime.xml
@@ -198,6 +198,11 @@ if (($timestamp = strtotime($str)) === false) {
     some Linux distributions, and a few other operating systems. PHP 5.1.0 and
     newer versions overcome this limitation though.
    </para>
+   <para>
+    For 64-bit versions of PHP, the valid range of a timestamp is effectively
+    infinite, as 64 bits can represent approximately 293 billion years in either
+    direction.
+   </para>
   </note>
   <note>
    <para>