Definition of the UTC Time Standard

International standard notation

Date: YYYY-MM-DD (e.g. 2002-12-25 (i.e. 2002-December-25))
Time: 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

Since the introduction of an international atomic time scale in 1972, almost all existing civil time zones are now related to UTC, which replaced, and is slightly different from, GMT.

Why bother?

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