[LEAPSECS] Cost: getting rid of GMT & discontinuing leap seconds

ashtongj ashtongj at comcast.net
Sun Oct 24 14:41:25 EDT 2010

My replies are interspersed among Paul's questions.

On 2010-01-14 12:29 PM, p at 2038bug.com wrote:


>> it will be necessary to modify all [...]


> Why?

Because they will be wrong, civil time will not be based upon the mean
time an Greenwich, for any meaning of the word Greenwich.


>> It will also be necessary to. modify

>> all computer programs which keep civil time [...]


> Examples of such programs with a material manifestation of a problem?


No such examples exist yet. However, once the difference between UT1 and
UTC becomes great enough to matter in daily affairs, a person who would
benefit by interpreting a timestamp applied by some computer, where said
timestamp contains "GMT", can argue that it MUST mean UT1, and can't
possibly mean UTC, because the meridian for which UTC is the mean solar
time does not pass through Greenwich. For example, an advertisement for
bids states bids must be received by 24:00:00 UTC December 31, 2026. The
computer that receives such bids marks a bid as having been received at
00:00:02 January, 2027 GMT. The bidder sues, demanding that the bid be
accepted on the basis that GMT is UT1, UT1 runs 6 seconds in advance of
UTC, so the bid was received at 23:59:56 UTC and met the deadline.

Gerry Ashton

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