Merge pull request symfony#2403 from joelclermont/issue_2266

document DateType limitations

Author: weaverryan

reference/forms/types/options/_date_limitation.rst.inc

@@ -0,0 +1,5 @@
+.. caution::
+    
+    If ``timestamp`` is used, ``DateType`` is limited to dates between
+    Fri, 13 Dec 1901 20:45:54 GMT and Tue, 19 Jan 2038 03:14:07 GMT on 32bit
+    systems. This is due to a `limitation in PHP itself <http://php.net/manual/en/function.date.php#refsect1-function.date-changelog>`_.

reference/forms/types/options/date_input.rst.inc

@@ -12,4 +12,6 @@ your underlying object. Valid values are:
 * ``timestamp`` (e.g. ``1307232000``)
 
 The value that comes back from the form will also be normalized back into
-this format.
+this format.
+
+.. include:: /reference/forms/types/options/_date_limitation.rst.inc

reference/forms/types/options/date_widget.rst.inc

@@ -12,3 +12,5 @@ The basic way in which this field should be rendered. Can be one of the followin
 
 * ``single_text``: renders a single input of type text. User's input is validated
   based on the `format`_ option.
+
+.. include:: /reference/forms/types/options/_date_limitation.rst.inc