Only check that bills are advancing every 24 hours

The bulk data is only updated every 24 hours, frustratingly.

cron/checks.php

@@ -48,14 +48,14 @@
         {
             $sql = 'SELECT *
                     FROM `bills_status`
-                    WHERE date_created > NOW() - INTERVAL 3 HOUR
+                    WHERE date_created > NOW() - INTERVAL 24 HOUR
                     ORDER BY date_created DESC';
             $result = mysql_query($sql);
             if (mysql_num_rows($result) == 0)
             {
-                $log->put('Error: No bills have advanced in the past 3 hours, which is unusual. '
-                    . 'There may be a problem. Make sure that summaries.csv is being updated, and '
-                    . 'that data is being loaded correctly.', 6);
+                $log->put('Error: No bills have advanced in the past 24 hours. Bill histories are '
+                    . 'not being updated. Make sure that history.csv is being updated, and that '
+                    . 'data is being loaded correctly.', 6);
             }
         }
     }