XPost: comp.lang.c, comp.lang.c++   
   From: F.Zwarts@HetNet.nl   
      
   Op 02.feb.2026 om 22:23 schreef Lawrence D’Oliveiro:   
   > On Mon, 2 Feb 2026 11:18:03 +0100, Fred. Zwarts wrote:   
   >   
   >> Op 01.feb.2026 om 10:06 schreef Lawrence D’Oliveiro:   
   >>>   
   >>> On Sat, 31 Jan 2026 16:10:38 -0600, Gary Scott wrote:   
   >>>   
   >>>> Flexibility is taken to a bit extreme in GINO graphics libraries   
   >>>> (a UK product), with a calendar that goes all the way back to   
   >>>> 1066...:)   
   >>>   
   >>>       ldo@theon:~> date -d "1-Jan-1066"   
   >>>       Mon 01 Jan 1066 00:00:00 LMT   
   >>>       ldo@theon:~> date -d "1-Jan-966"   
   >>>       Wed 01 Jan 0966 00:00:00 LMT   
   >>>       ldo@theon:~> date -d "1-Jan-866"   
   >>>       Fri 01 Jan 0866 00:00:00 LMT   
   >>   
   >> Now it becomes important to indicate whether the Gregorian or the Julian   
   >> calendar is used.   
   >   
   >      ldo@theon:~> date -d 4-oct-1582   
   >      Mon 04 Oct 1582 00:00:00 LMT   
   >      ldo@theon:~> date -d 15-oct-1582   
   >      Fri 15 Oct 1582 00:00:00 LMT   
   >   
   > Proleptic Gregorian.   
   >   
   >> Not all countries switched at the same date.   
   >   
   >      ldo@theon:~> ncal -s IT oct 1582   
   >          October 1582   
   >      Mo  1 18 25   
   >      Tu  2 19 26   
   >      We  3 20 27   
   >      Th  4 21 28   
   >      Fr 15 22 29   
   >      Sa 16 23 30   
   >      Su 17 24 31   
   >      ldo@theon:~> ncal -s GB oct 1582   
   >          October 1582   
   >      Mo  1  8 15 22 29   
   >      Tu  2  9 16 23 30   
   >      We  3 10 17 24 31   
   >      Th  4 11 18 25   
   >      Fr  5 12 19 26   
   >      Sa  6 13 20 27   
   >      Su  7 14 21 28   
   >      ldo@theon:~> ncal -s GB sep 1752   
   >          September 1752   
   >      Mo    18 25   
   >      Tu  1 19 26   
   >      We  2 20 27   
   >      Th 14 21 28   
   >      Fr 15 22 29   
   >      Sa 16 23 30   
   >      Su 17 24   
      
   What I meant is that the calender should be added in the output. We add   
   a time-zone to avoid confusion, for such old dates the calendar should   
   be added as well to avoid confusion.   
   When the country, e.g. IT is known, then we don't need a time zone or   
   calendar, strictly speaking, because it can be looked up somewhere, but   
   not everyone knows the time zone and the calendar switch by heart and it   
   saves time to add them both.   
   Another thing is that time zones did not exist centuries ago. Every   
   place had its own local time.   
   But how serious should we be?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)