--- a/toolkit/content/widgets/datetimebox.xml
+++ b/toolkit/content/widgets/datetimebox.xml
@@ -1219,19 +1219,21 @@
             field.setAttribute("rawValue", "");
             // Minimum digits to display, padded with leading 0s.
             field.setAttribute("mindigits", aMinDigits);
             // Maximum length for the field, will be advance to the next field
             // automatically if exceeded.
             field.setAttribute("maxlength", aMaxLength);
 
             if (this.mIsRTL) {
-              // Override the numeric field with "ltr", so that it stays in the
-              // same order even when it's empty (with placeholder).
-              field.style.unicodeBidi = "bidi-override";
+              // Force the direction to be "ltr", so that the field stays in the
+              // same order even when it's empty (with placeholder). By using
+              // "embed", the text inside the element is still displayed based
+              // on its directionality.
+              field.style.unicodeBidi = "embed";
               field.style.direction = "ltr";
             }
           }
 
           return field;
         ]]>
         </body>
       </method>