Re: Leap Year..................!, leap seconds...

On Tue, 8 Sep 1998, Helmut Leininger wrote: > Peter Lancashire wrote: > > Richard Thomas wrote: > > > In any case, 2000 is a leap year, and February has 29 days. 1900 was > > > not a leap year. [...] > > > > > We sometimes have leap-seconds but I am not aware of the rule used to > > invoke them. This would be a real challenge... The rule is that the earth's rotation has fallen out of synchronization with the atomic clocks by enough (more than half a second, I think) to warrant introducing a leap second. There are all sorts of discussions on this in the comp.lang.c.moderated and comp.std.c newsgroups at the moment. > > Meanwhile, those of us in the UK have a mundane and infuriating time > > problem: the lack of a rule for deciding on the switch to and from > > summer time (daylight savings to my readers in the USA). It is decided > > by "Orders in Council". Anyone know the algorithm for this? ;-) > > Ain't this the last Sunday in March (02:00:00) to switch to summertime and the > last sunday in October (03:00:00) to switch back ? It tends to correspond to a rule like that (though the switch back also occurs at 02:00) but as Peter said, it is enacted by 'Orders in Council' each year. That means that someone in government somewhere decides which two dates will be used in each year; this may or may not correspond to your rule. And it is done each year, rather than for several years in advance. Once upon a long time ago (early 1970's, I think, though it could even have been the late 60's), Britain experimented with double-summer-time during the summer (2 hours ahead of GMT or UTC), and summer-time during the winter. I remember being given reflective armbands to wear on the way to/from school because it was inevitably dark when we got home -- I said it was a long time ago. That was (probably) ordained by orders in council rather than statute law, though it was discussed in parliament before the orders were made. Yours, Jonathan Leffler (jleffler@informix.com) #include <witticism.h> Guardian of DBD::Informix v0.60 -- http://www.perl.com/CPAN Informix IDN for D4GL & Linux -- http://www.informix.com/idn