UTC - Universal Time Co-ordinated

Notation

International standard date notation:

• YYYY-MM-DD (e.g. 2002-12-25 (i.e. 2002-December-25)).

International standard time of day notation:

• hh:mm:ss (e.g. 23:59:59).

Time Zone

Without any further additions, a date and time as written above is assumed to be in some local (possibly unknown) time zone. The suffix 'UTC' indicates the time is quoted in Universal Time Coordinated, for example, 2002-12-25 23:59:59 UTC

UTC was called Greenwich Mean Time (GMT) before 1972, however this term, strictly speaking, should no longer be used. Since the introduction of an international atomic time scale, almost all existing civil time zones are now related to UTC, which is slightly different from the old GMT.

NOTE: Where GMT is quoted, this in fact refers to UTC.

Why bother?

Using a standard time notation, allows anyone in the world to:

• know exactly what your time means, relative to, and regardless of, where they are in the world;
• easily and quickly convert your time into their local time.

Not everyone, who has access to a web site, is living in the same month, year or century as the web site location.