
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 24:00:00. 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. Dave C. Groton, CT