On Thu, 30 Oct 2008 10:48:29 -0400, J R wrote: >> I wish all computers did time-date stamps in Zulu, and only translated >> to local time as needed. > >Hear, hear! > +1
>> (Heck, I wish Daylight Savings Time would go away, and wouldn't be >> adverse if local time would go away.) > >Hear, hear! > Unrealistic. "When in Rome (or Indiana, or Arizona), ..." >BTW, I always feel sorry for the Zulus -- there's a time zone out there >with their name on it and it's not theirs. :-( > >> Date: Thu, 30 Oct 2008 08:06:41 -0600 >> From: howard.brazee >> >> On 30 Oct 2008 03:11:32 -0700, (Paul Gilmartin) wrote: >> >> >Will these get the Daylight Saving Time offset correct for dates both >> >before and after 2006 (in the U.S.)? >> > >> >Will these get the Leap Second offset correct for dates back to 1972 >> >when leap seconds were instituted? (How do "Lilian" seconds account >> >for Leap Seconds? If done correctly there's a simple affine conversion >> >from (E)TOD values to Lilian seconds.) >> >> I'm curious. What business needs do you have that require past >> Daylight Savings Times and leap seconds? >> I'm not on the business side so I can only conjecture. But I can readily imagine legal consequences depending on whether a prior event occurred before or after midnight. The conversion is not rocket science. Most Unix systems with which I have worked correctly convert GMT to civil time for dates back to 1970, and for time zones around the world. z/OS Unix is correct only back to 2007 (in the U.S.), and Classic z/OS knows only the current offset, and for only a single time zone other than GMT (or does LE do better, nowadays?) Leap seconds are a PITA. I'd like to reflect your question to IBM: What customers' business needs was IBM addressing in choosing to run the TOD clock on IAT (minus ten seconds), rather than on UT1 which would avoid the discontinuities of leap seconds. While IBM is ahead of the crowd in recognizing leap seconds, the implementation is lackadaisical. An enthusiastically faithful implementation would, when TIME was called in the middle of a leap second, return 23:59:60.500, the correct UTC. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
