Hi Brian, Paul, On Tue, Feb 11, 2025 at 01:20:33PM -0700, Brian Inglis wrote: > Hi Alex, > > Use "T0" or " 0" zone offset prefix to make it work:
Hmmm, T0 is nice. It's not exactly a time without a date, but it can be a workaround. As in, "I just don't care about the time; I'll put a 0". > > $ date -d2023-09-20T0+0200 > 2023 Sep 19 Tue 16:00:00 > $ date -d2023-09-20\ 0+0200 > 2023 Sep 19 Tue 16:00:00 > > or maybe add [ T]12:00 to make it less ambiguous when dealing only with dates? 12:00 is ambiguous too. As Paul pointed out back in August, there have been days with 48 hours, and I suspect other days have been much shorter than 24 hours. In such cases, the 12:00 trick wouldn't be enough to avoid ambiguity. Also, I think timezones 13 hours away from UTC do exist or have existed in the past, no? I'd prefer a solution that avoids any ambiguity (or one that keeps the ambiguity by not specifying a time at all). > I agree that date with zone without time has a useful meaning, so allowing > the time to be optional, defaulting to 0 as usual, in strptime(3) and > date(1), would be useful. Yeah, I guess T0 is a nice workaround. > > > Now I remember, coreutils uses gnulib for that, as you told me some time > > > ago. It would be a gnulib report. :) > > Didn't you all go around on this last August in bug-gnulib? Ahhh, I had forgotten about that thread. Yes we did. <https://lists.gnu.org/archive/html/bug-gnulib/2024-08/msg00003.html> We didn't really reach a consensus, though. I now see a comment from Paul from back then: | Fourth, RFC 9557 section 1.2 strongly discourages suffixes like | "[+02:00]". That suffix means clocks never change in that location, | which is historically inaccurate everywhere. Instead, you're supposed | to use a suffix like "[Africa/Tripoli]". I view this as a major | objection to Alejandro's proposal for the output of "passwd". I guess I could use [UTC]. Since I only want to print UTC dates, that should work. Does that sound more palatable? | It might make sense to extend parse-datetime (and GNU date -d) to | parse RFC 9557 [time-zone] suffixes, should they become popular. | However, none of this should be needed for the 'passwd' command. For | that, it's probably better just to stick with its current output, | which is just a date without time zone I'm not happy about it. A date without a time zone is understood as a local date. However, what we store are UTC dates, so we'de be misleading the reader. I insist on a method for printing a date with a timezone but without a time. I'm especially interested in the UTC timezone. Have a lovely night! Alex -- <https://www.alejandro-colomar.es/>
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