mailing list of musl libc
 help / color / mirror / code / Atom feed
From: Alexander Weps <exander77@pm.me>
To: musl@lists.openwall.com
Subject: Re: [musl] Broken mktime calculations when crossing DST boundary
Date: Tue, 26 Mar 2024 18:56:13 +0000	[thread overview]
Message-ID: <vj3lZzqBWSLmtJX2CO2PHMlSZJcNWRsceJ4ziy-3uTT259cT1vTBfmqpGqwF8kVPPX-YAZ2hDAF1Szgt4jwkAl_GwkB_FOlk2SKm6psSBtM=@pm.me> (raw)
In-Reply-To: <Pine.BSM.4.64L.2403252321540.3887@herc.mirbsd.org>

>
> > Show me a function implementation that produces same time next day
> > under this behavior you assume to be correct.
>
>
> It is not possible to do that with mktime. You’ll have to do
> that yourself. POSIX even says so.
>
> It does indicate that on implementations (their word for libcs
> here) that follow its recommendation to not normalise tm_sec,
> you can achieve the desired effect by adding 86400 to it, though
> that will not work right in the presence of a leap second on
> systems honouring them (which is a deviation from POSIX, of
> course).
>
> Adding 86400 to the time_t value, under the same leap second
> caveat, can work if your code can rely on POSIX (ISO C does not
> specify the internal structure of time_t).

Doesn't work, this will not give the same time next day, this fails on STD/DST changes.

Because same time next day is not always 86400 apart.

>
> bye,
> //mirabilos
> --
> 22:20⎜<asarch> The crazy that persists in his craziness becomes a master
>
> 22:21⎜<asarch> And the distance between the craziness and geniality is
>
> only measured by the success 18:35⎜<asarch> "Psychotics are consistently
>
> inconsistent. The essence of sanity is to be inconsistently inconsistent

  parent reply	other threads:[~2024-03-26 18:56 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-24 13:36 Alexander Weps
2024-03-24 16:59 ` Alexander Weps
2024-03-24 17:04 ` Rich Felker
2024-03-24 17:12   ` Alexander Weps
2024-03-24 18:00     ` Alexander Weps
2024-03-24 18:02     ` Rich Felker
2024-03-24 18:16       ` Alexander Weps
2024-03-24 18:24         ` Rich Felker
2024-03-24 18:36           ` Alexander Weps
2024-03-24 19:01             ` Joakim Sindholt
2024-03-24 19:05               ` Alexander Weps
2024-03-24 19:06             ` Alexander Weps
2024-03-24 19:13               ` Alexander Weps
2024-03-24 19:13               ` Alexander Weps
2024-03-24 19:22             ` Rich Felker
2024-03-24 19:57               ` Alexander Weps
2024-03-24 20:22                 ` Rich Felker
2024-03-24 20:50                   ` Alexander Weps
2024-03-24 21:43                     ` Alexander Weps
2024-03-24 23:51                 ` Thorsten Glaser
2024-03-25  0:36                   ` Alexander Weps
2024-03-25 11:52                     ` Alexander Weps
2024-03-25 12:21                       ` Rich Felker
2024-03-25 12:55                         ` Alexander Weps
2024-03-25 13:08                           ` Rich Felker
2024-03-25 13:13                             ` Alexander Weps
2024-03-25 13:13                           ` Rich Felker
2024-03-25 13:24                             ` Alexander Weps
2024-03-25 13:42                               ` Rich Felker
2024-03-25 13:48                                 ` Alexander Weps
2024-03-25 13:50                                   ` Alexander Weps
2024-03-25 18:02                                 ` Rich Felker
2024-03-25 18:28                                   ` Alexander Weps
2024-03-25 18:53                                     ` Rich Felker
2024-03-25 18:57                                       ` Alexander Weps
2024-03-25 19:38                                         ` Rich Felker
2024-03-25 19:47                                           ` Rich Felker
2024-03-25 20:05                                             ` Alexander Weps
2024-03-25 20:12                                               ` Alexander Weps
2024-03-25 20:00                                           ` Alexander Weps
2024-03-25 20:23                                             ` Rich Felker
2024-03-25 20:31                                               ` Rich Felker
2024-03-25 23:19                                     ` Thorsten Glaser
2024-03-25 23:16                                 ` Thorsten Glaser
2024-03-25 13:44                               ` Alexander Weps
2024-03-25 22:40                           ` Thorsten Glaser
2024-03-25 22:59                             ` Alexander Weps
2024-03-25 23:34                               ` Thorsten Glaser
2024-03-26 12:45                                 ` Alexander Weps
2024-03-26 21:59                                   ` Thorsten Glaser
2024-03-27  0:14                                     ` Alexander Weps
2024-03-27  0:38                                       ` Alexander Weps
2024-03-27  1:35                                       ` Thorsten Glaser
2024-03-27  2:45                                         ` Alexander Weps
2024-03-27  4:42                                           ` Thorsten Glaser
2024-03-26 18:56                                 ` Alexander Weps [this message]
2024-03-25 23:13                             ` Rich Felker
  -- strict thread matches above, loose matches on Subject: below --
2024-03-22 19:56 Alexander Weps
2024-03-23  6:41 ` Markus Wichmann
     [not found]   ` <528SeRFaPfDw7fA4kqKDlio1U4RB_t9nmUemPcWw9_t1e2hBDpXYFmOqxAC37szgYvAVtmTuXWsmT64SSN3cSQFVdrQqXUAgkdTMPZQ0bg0=@pm.me>
2024-03-23 10:38     ` Markus Wichmann
2024-03-23 11:59       ` Alexander Weps
2024-03-23 12:00         ` Alexander Weps
2024-03-23 12:31           ` Rich Felker
2024-03-23 13:49             ` Alexander Weps
2024-03-23 15:31               ` Rich Felker
2024-03-23 16:54                 ` Alexander Weps
2024-03-23 18:57                   ` Alexander Weps
2024-03-23 19:33                     ` Alexander Weps
2024-03-23 20:18                     ` Rich Felker
2024-03-23 20:40                       ` Alexander Weps
2024-03-24  0:36                         ` Eric Pruitt
2024-03-24  2:04                         ` Rich Felker
2024-03-24  3:32                           ` Daniel Gutson
2024-03-24 11:05                             ` Alexander Weps
2024-03-24 13:24                               ` Alexander Weps
2024-03-23 12:01         ` Alexander Weps

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='vj3lZzqBWSLmtJX2CO2PHMlSZJcNWRsceJ4ziy-3uTT259cT1vTBfmqpGqwF8kVPPX-YAZ2hDAF1Szgt4jwkAl_GwkB_FOlk2SKm6psSBtM=@pm.me' \
    --to=exander77@pm.me \
    --cc=musl@lists.openwall.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/musl/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).