Class it:

/**
 * Append all arguments to a logfile (tab separated). Date will be added to filename and line
 * @param $name Name of logfile. Will be in log/ of service unless it starts with /
 * @param $args Varargs to log, will be tab separated.
 */
static function log($name, ...$args)
{
    $line = date("Y-m-d H:i:s") . "\t" . implode("\t", $args);
    self::log_line($name, $line);
    return $line;
}