epoch_to_time.go

// ConvertTS converts a UNIX timestamp string (with sub second precision) "epoch" into a time.Time
// (c) Florent CHAUVEAU <florent.chauveau@gmail.com>

func ConvertTS(ts string) time.Time {
	value := strings.SplitN(ts, ".", 2)

	var sec int64
	var nsec int64

	if len(value) == 0 {
		return time.Time{}
	}

	if len(value) == 1 {
		sec, _ = strconv.ParseInt(value[0], 10, 64)
	} else if len(value) == 2 {
		sec, _ = strconv.ParseInt(value[0], 10, 64)
		nsec, _ = strconv.ParseInt(value[1], 10, 64)

		// "1527589078.5418"    -> 541800000 nsec
		// "1527589067.8157027" -> 815702700 nsec
		// "1527589073.0891006" ->  89100600 nsec
		// "          .000000001" (1 nsec)
		// "          .000000042" (42 nsec)
		// "          .000000423" (423 nsec)

		x := 9 - len(value[1])

		if x > 0 {
			// "5418" becomes 541800000
			// "0891006" becomes 89100600
			// "000000001" stays 000000001
			nsec = nsec * int64(math.Pow10(x))
		}
	}

	return time.Unix(sec, nsec).UTC()
}