24:00 versus 23:59:59--insights?
Dave at Cantor.mv.com
Tue Apr 28 16:12:44 UTC 2009
On 28-Apr-2009, Olson, Arthur David (NIH/NCI) wrote:
> There are a few places with rules such as "... lastFri 0:00 ..." that
> should be "... lastThu 24:00 ..."
> One possibility is to rewrite the rules that way; doing so buys error
> messages from pre-1998 versions of zic.
> Another possibility is to rewrite the rules as "... lastThu 23:59:59
> ..." which works with pre-1998 versions of zic but is a second off. A
> third way is to use 24:00 and, where it is used, include a comment about
> either upgrading zic or using the 23:59:59 dodge. I'd appreciate any
> insights on how to go forward.
Strictly my personal opinion, I think that we should use
A related question: is it possible for a jurisdiction to specify
a rule that says something like the time change will occur at one
minute after 24:00 on the second Thursday? That's not the same
thing as 0:01 on the second Friday. It's 0:01 on Friday after
the second Thursday, and there is no current way to express that
(that I could find). Do we need to allow times like 24:01 or
even 25:00? I don't need answers now; I'm just raising the
questions for thought. Perhaps we shouldn't worry about it
until and unless something like that happens. I think it's
unlikely, but possible, for awful rules like that to occur.
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