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From: random832@fastmail.com (Random832)
Subject: [TUHS] Date madness
Date: Thu, 14 Dec 2017 22:04:49 -0500	[thread overview]
Message-ID: <1513307089.3651124.1205701656.4E468085@webmail.messagingengine.com> (raw)
In-Reply-To: <1513220855.2223106.1204498584.3CB1C63A@webmail.messagingengine.com>

On Wed, Dec 13, 2017, at 22:07, Random832 wrote:
> Making V6 do it (no long *or* unsigned type) is a bit more involved, but
> I'm close to something viable. Incidentally, one gotcha I've run into is
> that the code as-is passes the year minus 1900 to dysize, whereas modern
> dysize implementations that respect the 100 and 400 year rules require
> the full year.

I managed to get it working - an implementation that works on V6 (well,
works on apout with the V6 compiler and library) for all dates between
1970-01-01 and 2106-02-07 06:28:15. I even tried to do as much as
possible in the register variables, to approximate the same performance
as the original (though I suspect the O(N) year incrementing loop
probably doesn't perform as well now as it did in 1975, especially with
a proper dysize implementation)

Other features: localtime supports all correct US rules and offsets
greater than 9 hours (though it still has the US rules and EST
hardcoded), and ctime supports Y2K (and 2.1K)

If anyone wants it I can post it somewhere, or just put it on the list.


  reply	other threads:[~2017-12-15  3:04 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-13 19:12 Doug McIlroy
2017-12-14  3:07 ` Random832
2017-12-15  3:04   ` Random832 [this message]
  -- strict thread matches above, loose matches on Subject: below --
2017-12-16 10:50 Doug McIlroy
2017-12-16 16:11 ` Random832
2017-12-16 17:11   ` Ralph Corderoy
2017-12-13 22:16 Norman Wilson
2017-12-14  0:24 ` Chris Torek
2017-12-17 16:20   ` Ron Natalie
2017-12-17 18:53     ` Tom Ivar Helbekkmo
2017-12-17 20:07       ` Ron Natalie
2017-12-13 20:22 Noel Chiappa
2017-12-13 17:16 Noel Chiappa
2017-12-13 18:53 ` Tom Ivar Helbekkmo
2017-12-13 20:46 ` arnold
2017-12-15 16:41   ` Paul Winalski
2017-12-15 17:19     ` Dave Horsfall
2017-12-16 15:45     ` Clem Cole
2017-12-16  3:39   ` Dave Horsfall
2017-12-16  3:45     ` Lyndon Nerenberg
2017-12-17  1:43       ` Dave Horsfall
2017-12-14  3:08 ` Dave Horsfall
2017-12-14  3:13   ` Warner Losh
2017-12-13 16:31 Noel Chiappa
2017-12-13 16:50 ` arnold
2017-12-13 16:08 Noel Chiappa
2017-12-13 16:23 ` arnold
2017-12-13 15:56 Noel Chiappa
2017-12-12 18:31 Noel Chiappa
2017-12-12 18:01 Noel Chiappa
2017-12-12 18:21 ` Warner Losh
2017-12-13 15:07 ` Random832
2017-12-13 17:00   ` Jason Stevens
2017-12-13 17:18     ` Ron Natalie
2017-12-13 18:02       ` Arthur Krewat
2017-12-13 15:39 ` Wolfgang Helbig
2017-12-14  0:57 ` Dave Horsfall
2017-12-14 14:09   ` William Cheswick
2017-12-17 16:19     ` Ron Natalie
2017-12-17 16:33       ` William Cheswick
2017-12-17 17:54         ` Random832
2017-12-17 22:15           ` Dave Horsfall
2017-12-17 22:54             ` Ian Zimmerman
2017-12-16 18:12 ` Wolfgang Helbig

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