Work out utc offset instantly with clear inputs, formula shown and shareable results.
The UTC offset is local time minus UTC, wrapped into the valid range of -12 to +14. Local 15:30 against 12:00 UTC gives +3:30. Offsets outside whole hours exist because several countries chose 30 or 45 minute alignments to better match local solar time.
UTC offset
offset = local time - UTC, wrapped into -12 to +14
Notation
written as UTC+hh:mm or UTC-hh:mm
Because Kiribati moved the Line Islands across the date line in 1995 to share a working week with Asia, creating UTC+14.
Practically, though not technically. UTC is an atomic time standard with leap seconds; GMT is a time zone based on the Greenwich meridian.