[LEAPSECS] Footnote about CCITT and UTC

Zefram zefram at fysh.org
Fri Dec 12 17:34:04 EST 2008

Tom Van Baak wrote:

>Does anyone know much time ISO spends defining leap days,

>or does everyone just take them for granted? Is there official

>text on the definition.

ISO 8601 fully defines the Gregorian calendar, including the complete
leap day rule. It says relatively little about leap seconds and UTC.
The attitude of the standard is that leap days are an inherent part of the
Gregorian-based date formats, but leap seconds are merely a peculiarity
of one of many possible ways to count time of day. It's neutral about
whether and when leap seconds may occur: that's an application issue.
The timezone designators are specifically described as being relative
to UTC, but it is more consistent with the rest of the standard to treat
that mention of UTC as actually referring to vague UT.


More information about the LEAPSECS mailing list