Rob Seaman said:
> I have heard no response to my discussion of techniques for achieving
> synchronization - of the difference between naive "fall back" hours
> and 25 hour days.  But how in practice is it envisaged that a scheme
> for migrating time zones versus TAI would work, precisely?

In the short term, by modifying the UTC-LTC function by adding a secular
term to the periodic one. Thus at present the function in the UK is:

    dayofyear in [Last Sunday in Mar .. Last Sunday in Oct] ? 3600 : 0.

This would change to:

    (dayofyear in [Last Sunday in Mar .. Last Sunday in Oct] ? 3600 : 0) +
    (year < 2600 ? 0 : year < 3100 ? 3600 : year < 3500 ? 7200 : ...)

or whatever. Note that we already have similar levels of complexity in
dealing with the changing summer time dates, the British Standard Time
folly, BDST during the war, and so on.

Note also that the Olsen tz code handles all of this just fine.

> Note, for
> instance, that nothing short of redefining the second can avoid the
> quadratic acceleration between the stage one and stage two clocks.
> Time zones (and the prime meridian?) would race more-and-more rapidly
> around the globe.

At some point, probably around the time that we're seeing an hourly shift
every year, people are going to have to divorce "second" from "day", or at
least re-negotiate the terms of engagement.

Clive D.W. Feather  | Work:  <[EMAIL PROTECTED]>   | Tel:    +44 20 8495 6138
Internet Expert     | Home:  <[EMAIL PROTECTED]>  | Fax:    +44 870 051 9937
Demon Internet      | WWW: | Mobile: +44 7973 377646
Thus plc            |                            |

Reply via email to