Added Ticktock of the Clock Restarts Time Debate

Unix time is based upon the number of seconds after the initial date of Jan. 1, 1970. This was a very wise choice, and leap seconds were expected to be included.

Unix time will not have any problems until the year 2037, because of a potential floating point error. Like Y2K, this will be dealt with properly.

Thanks for the link. That was one I'd seen before when this issue of eliminating leap seconds first came up. There are some really interesting (though esoteric) links there.

My first choice when I want to know something about official timekeeping is the Navy's Directorate of Time page. They've got some cool resources.

Info from the USNO (and I thought GPS clocks were on time!):

U.S. NAVAL OBSERVATORY
WASHINGTON, D.C. 20392-5420

July 27, 2005
No. 69

TIME SERVICE ANNOUNCEMENT SERIES 14

UTC TIME STEP

1. The International Earth Rotation and Reference Systems Service (IERS) has
announced the introduction of a time step to occur at the end of December, 2005.

2. Coordinated Universal Time (UTC) will be retarded by 1.0s so that the
sequence of dates of the UTC markers will be:

2005 December 31 23h 59m 59s
2005 December 31 23h 59m 60s
2006 January 01 0h 0m 0s

3. The difference between UTC and International Atomic Time (TAI) is:

from 1999 01 Jan, UTC to 2006 01 January, UTC: TAI-UTC= +32s
from 2006 01 Jan, UTC until further notice: TAI-UTC= +33s

4. Information regarding current and predicted values of UT1-UTC is provided in
IERS Bulletin A.

5. UTC and all time scales based on UTC will be affected by this adjustment.
However, Loran-C and GPS will not be adjusted physically. Times of Coincidence
for LORAN-C are available on the Time Service Web Page
(http://tycho.usno.navy.mil/loran.html). For GPS, the leap second correction
contained within the UTC data of subframe 4, page 18 of the navigation message
transmitted by satellites will change.

Before the leap second
GPS-UTC = +13s (i.e., GPS is ahead of UTC by thirteen seconds)

After the leap second
GPS-UTC = +14s (i.e., GPS will be ahead by fourteen seconds)

Wouldn't it be easier just to speed up the earth a bit? :-)

If you got a spare Gigawatt. The length of day increases about 0.002 seconds per century because of drag of the Earth's tidal bulge on the moon, transferring angular momentum from the Earth to the Moon. It causes the Moon's orbit to lengthen by about 0.01 meters per century. As tiny as this effect seems, it means a transfer of about one billion watt-seconds of energy per second.

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