Validate that the time values convert to something usable.
public function validateValidTime(&$form, $operator, $value) {
$operators = $this
->operators();
if ($operators[$operator]['values'] == 1) {
$convert = strtotime($value['value']);
if (!empty($form['value']) && ($convert == -1 || $convert === FALSE)) {
form_error($form['value'], t('Invalid date format.'));
}
}
elseif ($operators[$operator]['values'] == 2) {
$min = strtotime($value['min']);
if ($min == -1 || $min === FALSE) {
form_error($form['min'], t('Invalid date format.'));
}
$max = strtotime($value['max']);
if ($max == -1 || $max === FALSE) {
form_error($form['max'], t('Invalid date format.'));
}
}
}