On Sun, 8 Sep 2013 16:22:53 -0400, John Gilmore wrote: >I'm not sure I understand Paul's last post. > >z/OS does keep the current leap-second count at hand. This value >changes at most twice a year, at the end of June and at the end of >December; and ample advance notice, at least six months' notice under >BIPM's rules, is given of an impending increment or decrement. > I thought it was four months. Whatever. But it does not keep a record of the change history, necessary for converting archival timestamps, assuming they were recorded in (E)TOD format.
>Consulting a real-time data base in these circumstances seems to me to >be overkill. Why not update a static table? > Agreed. Consider the static table to be a cache of the data base, updated as necessary, which is seldom. In fact, I think ICANN and IERS supply only flat files, to be formatted as necessary. The multiplicity rises for civil time zones, but a static table in (virtual) memory, suitably indexed, may still be the right approach. UNIX likes to use filesystem directories as pseudo-KSDS indices. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
