diff --git a/manual/gui.rst b/manual/gui.rst
index b7cd4230bf..e7d8a4f616 100755
--- a/manual/gui.rst
+++ b/manual/gui.rst
@@ -367,6 +367,8 @@ For example::
 
     date:>10daysago
     date:<=45daysago
+	
+To avoid potential problems with translated strings when using a non-English version of calibre, the strings ``_today``, ``_yesterday``, ``_thismonth``, and ``_daysago`` are always available. They are not translated.
 
 You can search for books that have a format of a certain size like this::