What causes "invalid offset minutes: %d: %s" in kataras/iris?

Correct the offset so minutes are within 0–59 (e.g. '+03:59:00').

invalid offset minutes: %d: %s

Error message

invalid offset minutes: %d: %s

What it means

After parsing the minutes of an unconventional '+HH:MM:SS' offset, adjustForUnconventionalOffset rejects minute values greater than 60. A real timezone offset never has more than 59 minutes (60 is tolerated here as an edge case), so larger values indicate a malformed offset.

Source

Thrown at x/jsonx/iso8601.go:249

	if len(offsetParts) != 3 {
		return time.Time{}, fmt.Errorf("invalid offset format: %s", offset)
	}

	hours, err := strconv.Atoi(offsetParts[0])
	if err != nil {
		return time.Time{}, fmt.Errorf("error parsing offset hours: %s: %w", offset, err)
	}

	if hours > 24 {
		return time.Time{}, fmt.Errorf("invalid offset hours: %d: %s", hours, offset)
	}

	minutes, err := strconv.Atoi(offsetParts[1])
	if err != nil {
		return time.Time{}, fmt.Errorf("error parsing offset minutes: %s: %w", offset, err)
	}
	if minutes > 60 {
		return time.Time{}, fmt.Errorf("invalid offset minutes: %d: %s", minutes, offset)
	}

	seconds, err := strconv.Atoi(offsetParts[2])
	if err != nil {
		return time.Time{}, fmt.Errorf("error parsing offset seconds: %s: %w", offset, err)
	}

	if seconds > 60 {
		return time.Time{}, fmt.Errorf("invalid offset seconds: %d: %s", seconds, offset)
	}

	totalOffset := time.Duration(sign) * (time.Duration(hours)*time.Hour + time.Duration(minutes)*time.Minute + time.Duration(seconds)*time.Second)
	return t.Add(-totalOffset), nil
}

// UnmarshalJSON parses the "b" into ISO8601 time.
func (t *ISO8601) UnmarshalJSON(b []byte) error {
	if len(b) == 0 {

View on GitHub (pinned to 7bedaf55a0)

Solutions

Correct the offset so minutes are within 0–59 (e.g. '+03:59:00').
Check the producer for field-order or width bugs when composing the offset string.
Validate offsets at ingestion with a regex before parsing (e.g. ^[+-]\d{1,2}:[0-5]\d:[0-5]\d$).

Example fix

// before
ParseISO8601("2024-01-02T15:04:05+03:90:00") // invalid offset minutes: 90
// after
ParseISO8601("2024-01-02T15:04:05+03:30:00")

Defensive patterns

Strategy: validation

Validate before calling

func offsetMinutesInRange(ts string) bool {
	i := strings.LastIndexAny(ts, "+-")
	if i < 0 { return false }
	parts := strings.Split(ts[i+1:], ":")
	if len(parts) != 3 { return false }
	m, err := strconv.Atoi(parts[1])
	return err == nil && m >= 0 && m <= 59
}

Try / catch

tt, err := jsonx.ParseISO8601(s)
if err != nil {
	if strings.Contains(err.Error(), "invalid offset minutes") {
		return fmt.Errorf("timestamp %q has out-of-range offset minutes", s)
	}
	return err
}

Prevention

Validate offset minutes are 00–59 before parsing.
Watch for concatenation bugs in custom serializers.
Prefer standard +HH:MM offsets that avoid this code path.

When it happens

Trigger: ParseISO8601 on a timestamp with an offset like '+03:90:00' — minutes parse as an integer but exceed 60.

Common situations: Buggy serializers concatenating minutes and seconds (e.g. '3059' split wrongly); hand-built offset strings; corrupted data imports.

Related errors

AI-assisted analysis of kataras/iris@7bedaf55a0 (2026-08-30). Data as JSON: /api/errors/f87a1aa19ba008aa. Report an issue: GitHub.