PHP Fatal error: Uncaught Exception: DateTime::__construct()

The plugin was throwing this error:

PHP Fatal error: Uncaught Exception: DateTime::__construct(): Failed to parse time string (9 marzo, 2017) at position 5 (z): The timezone could not be found in the database in /httpdocs/wp-content/plugins/cache-control/cache-control.php:191

The page was returning a HTTP 500 Internal server error showing the white screen of death.

At cache-control.php line 191, i have seen:

$date_mod = new DateTime( get_the_modified_date() );

A date object is created from the string retrieved by get_the_modified_date()

At wordpress codex we can read that get_the_modified_date( $d, $post ) returns (string) the date on which the post was last modified. The function parameters are both optional and $d in particular is (string) (optional) Optional PHP date format. Defaults to the “date_format” option.

My wordpress installation is in Spanish and the date_format option is by default j F, Y. The date string retrieved by get_the_modified_date is not valid to create a new DateTime object.

To ensure that the $date_mod DateTime object is correctly created for any possible date_format option value, i have changed the line to this:

$date_mod = new DateTime( get_the_modified_date( 'Y-m-d' ) );

That way we ensure that the value retrived by get_the_modified_date is alwais going to be correct to create the $date_mod DateTime object no matter the date_format option value.

Here is the patch to fix the issue:

Index: trunk/cache-control.php
===================================================================
--- trunk/cache-control.php	(revision 1645039)
+++ trunk/cache-control.php	(working copy)
@@ -205,7 +205,7 @@
 
     if ( $option_name == 'singles' && get_option( 'cache_control_singles_mmulti' ) == 1 ) {
         $date_now = new DateTime();
-        $date_mod = new DateTime( get_the_modified_date() );
+        $date_mod = new DateTime( get_the_modified_date( 'Y-m-d' ) );
 
         $last_com = get_comments( 'post_id=' . get_the_ID() . '&number=1&include_unapproved=1&number=1&orderby=comment_date' );
         if ( $last_com != NULL ) {