On Wed, Oct 27, 2004 at 16:26:13 -0600,
Guy Fraser <guy@incentre.net> wrote:
>
> When calculating any usage based on time, it is a good idea to
> store usage in days:hours:minutes:seconds because they are static
> and stable, if you discount the deceleration of the earth and
> corrections in leap seconds for atomic clocks [see
> http://tycho.usno.navy.mil/leapsec.html ].
The length of calendar days isn't constant. In many timezones, one day a year
is 23 hours long and another is 25 hours long.
Having month and year intervals is useful for events that repeat monthly or
yearly in spite of there not being a constant number of seconds between
events.