UTC0400

UTC0400 is a time zone offset label indicating times four hours ahead of Coordinated Universal Time. It corresponds to UTC+04:00 and is sometimes written without a colon, as UTC0400. While UTC+04:00 is the standard way to present the offset in most contexts, some software and data formats omit the colon and store the offset as UTC0400.

Geographically, UTC+04:00 is used by several countries and territories in parts of the Middle East and the Indian Ocean region. Regions that currently observe UTC+04:00 include the United Arab Emirates, Oman, Azerbaijan, Georgia, Mauritius, and Seychelles. In these places, the offset is typically a year‑round standard time, with no daylight saving time. Other countries in the region have used UTC+04:00 in the past or during specific years or periods, sometimes adjusting to a different offset seasonally or for historical reasons.

In practice, there are variations in how this offset is represented. In ISO 8601, offsets are written with a colon, as +04:00. Software, databases, and APIs may accept either +04:00 or the compact form UTC0400, depending on the system. The IANA time zone database does not define a single “UTC0400” zone name; instead it provides region-based identifiers for locations that observe UTC+04:00, with fixed-offset representations available as needed for compatibility.