UTC time now (Coordinated Universal Time)

What UTC means

UTC stands for Coordinated Universal Time, the reference for every time zone. An offset such as UTC−5 or UTC+5:30 says how far a zone’s clocks are from it. UTC itself never changes for daylight saving time.

UTC vs GMT

UTC, Coordinated Universal Time, is the time scale on which every time zone is defined: New York is UTC−5 in winter, India is UTC+5:30. It is kept by atomic clocks and is not anybody’s local time in the political sense, although several countries use an offset of zero.

GMT, Greenwich Mean Time, began as mean solar time at the Royal Observatory in Greenwich. From 1884 until 1972 it was the international standard of civil time (Royal Museums Greenwich). Today its astronomical equivalent is UT1. Since 1972 leap seconds have kept UTC within 0.9 seconds of UT1, so for any clock that shows whole seconds, UTC and GMT are the same (NIST). The difference matters only to astronomers, navigators and the people who maintain time scales.

The name: the abbreviation UTC was chosen in 1970 so that neither English (CUT) nor French (TUC) word order was favoured (NIST). In practice, use “UTC” for technical work and “GMT” when you mean the winter time of the United Kingdom, where it is the legal time (GMT).

Leap seconds and the future of UTC

Because the Earth’s rotation is irregular, UTC has been kept close to UT1 by inserting leap seconds: 27 of them between 1972 and 2016, all positive. The last one was 23:59:60 UTC on December 31, 2016; since January 1, 2017, TAI − UTC = 37 seconds (IERS Bulletin C).

The IERS has announced no leap second for the end of December 2026. In October 2026 the General Conference on Weights and Measures decided that UTC will become continuous, meaning no further leap seconds, from May 20, 2027, and that the difference between UT1 and UTC may grow to as much as an hour (CGPM 2026, Resolution 5).

UTC in data: Z and +00:00

ISO 8601 and RFC 3339 write UTC as a trailing “Z” (2027-01-15T09:30:00Z) or as the offset +00:00. Aviation, shipping and the military read the Z aloud as “Zulu” (Zulu time). When you store timestamps, store UTC and keep the IANA zone of the event separately: an offset alone cannot tell you what the local time will be after the next clock change.

UTC converted to other zones

Every column is a fixed offset, so this table is valid on any date. Remember that the regions behind some columns switch to summer time (EST to EDT, CET to CEST, GMT to BST); the clock in those cities is then an hour later than the column.

Related zones and conversions

• UTC to IST
• UTC to EST
• IST to UTC
• Time zones of the world
• Daylight saving time
• Time zone converter