func formatPAXTime(ts time.Time) (s string) {
	secs, nsecs := ts.Unix(), ts.Nanosecond()
	if nsecs == 0 {
		return strconv.FormatInt(secs, 10)
	}

	// If seconds is negative, then perform correction.
	sign := ""
	if secs < 0 {
		sign = "-"             // Remember sign
		secs = -(secs + 1)     // Add a second to secs
		nsecs = -(nsecs - 1e9) // Take that second away from nsecs
	}