public static function getModifiedSinceHeader()
    {
        $modifiedSince = '';
        if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
            $modifiedSince = $_SERVER['HTTP_IF_MODIFIED_SINCE'];

            // strip any trailing data appended to header
            if (false !== ($semicolonPos = strpos($modifiedSince, ';'))) {
                $modifiedSince = substr($modifiedSince, 0, $semicolonPos);
            }
        }
        return $modifiedSince;
    }
public static function getModifiedSinceHeader()
    {
        $modifiedSince = '';
        if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
            $modifiedSince = $_SERVER['HTTP_IF_MODIFIED_SINCE'];

            // strip any trailing data appended to header
            if (false !== ($semicolonPos = strpos($modifiedSince, ';'))) {
                $modifiedSince = substr($modifiedSince, 0, $semicolonPos);
            }
        }
        return $modifiedSince;
    }
public static function getModifiedSinceHeader ( ) { $ modifiedSince = '' ; if ( isset ( $ _SERVER [ 'HTTP_IF_MODIFIED_SINCE' ] ) ) { $ modifiedSince = $ _SERVER [ 'HTTP_IF_MODIFIED_SINCE' ] ; // strip any trailing data appended to header if ( false !== ( $ semicolonPos = strpos ( $ modifiedSince , ';' ) ) ) { $ modifiedSince = substr ( $ modifiedSince , 0 , $ semicolonPos ) ; } } return $ modifiedSince ; }
Returns the If-Modified-Since HTTP header if it can be found. If it cannot be
found, an empty string is returned.

@return string
Returns the If - Modified - Since HTTP header if it can be found . If it cannot be found an empty string is returned .