Re: went pretty dang smoothly at this end

2006-01-01 Thread David Harper
On Sat, 31 Dec 2005, Rob Seaman wrote:
 Was watching and (the comparative clocks).
 Counted up to 23:59:60 (well, 16:59:60 in Tucson).  The GPS-UTC
 incremented as did the TAI-UTC.  The TV didn't melt down either.  No
 obvious Airbuses plummeting from the sky.  Life be good.

I was on board a United Airlines Boeing 777 en route from Chicago to
London. We were at 30,000 feet somewhere over eastern Canada when
the leap second occurred.

The first officer gave us a countdown to midnight in London, and
I'm happy to report that the plane failed to fall out of the sky,
explode, or otherwise deviate from its course at 23:59:60.

David Harper

Re: a system that fails spectacularly

2005-12-08 Thread David Harper

Poul-Henning Kamp wrote:

Some of us have been trying to drive this point though for some time:

  99.99% of all programmers have no idea what a leap-second is.

And these are the people who program the technology that runs our

The confusion runs deeper than that.

I discovered last year that implementations of Java up to and including
Java 1.3 did not implement the correct daylight saving time rules for
the United Kingdom during the period between 27 October 1968 and 31
October 1971 when the U.K. kept its clocks permanently one hour ahead of
GMT and called this British Standard Time.

The daylight saving time rules were implemented as little more than a
blanket starts on the last Sunday in March, ends on the last Sunday in
October prescription, with no provision for irregularities such as

As a result, Java programs would assume that the U.K. was keeping GMT
during the winter months of 1968/9, 1969/70 and 1970/1 when in fact the
clocks were an hour ahead.

This error was fixed in Java 1.4, when a rather more sophisticated
mechanism was added for handling daylight saving time rules, based upon
the Unix zoneinfo database, which does know about the irregularities
and exceptions.

When even Sun Microsystems can make this kind of mistake, with all of
the resources at its disposal, Joe or Jane Programmer working for a
small company can be forgiven for not being familiar with the arcane
world of leap seconds. There are, after all, only 102 of us on this
mailing list :-)

David Harper

Dr David Harper
Wellcome Trust Sanger Institute,  Hinxton,  Cambridge CB10 1SA,  England
Tel: 01223 834244 Fax: 494919

Re: a system that fails spectacularly

2005-12-07 Thread David Harper

Rob Seaman wrote:

I don't know whether to be more embarrassed for the company or for
the international standards process.  How many companies claim ISO
9000 conformance?  If they don't comprehend the requirements of
international standards pertaining to their products, how likely is
it that they comprehend their customers' requirements?

I am reminded of the Dilbert cartoon from way back when, in which the
pointy-haired boss is talking to a potential customer.

Customer: Your product looks good, but you can't be our supplier unless
yoru company is ISO 9000 certified.

PHB: So ... you don't care how bad our internal processes are, as long
as they're well-documented and used consistently.

Customer: That's right.

PHB: Our documented process says I must now laugh in your face and
double our price.

I think says everything you need to know about ISO 9000 in the real world.

David Harper

Dr David Harper
Wellcome Trust Sanger Institute,  Hinxton,  Cambridge CB10 1SA,  England
Tel: 01223 834244 Fax: 494919