Re: Fun With Dates -- Need Help

On Fri, 17 Jan 2025 20:54:34 +0000, Farley Flud wrote:

 
We see the jump and correct day with LO but not with the
GNU/Linux date/cal commands.  What is the problem?  What
am I doing wrong?
 

[Monospace font required]

Thanks a lot, assholes.  Thanks for fucking nothing.

I found the source of the problem all by my lonesome,
because you lackeys couldn't pull yourselves away from
your little kiddie games.

Now listen carefully.

Officially, the Gregorian calendar was introduced on
Oct 15, 1582.  The previous date, in the Julian calendar,
was Oct 4, 1582.  There is a jump from Oct 4 to Oct 15.

However, much of the rest of the world only adopted the
Gregorian calendar (GC) later.  In Britain and the Americas,
the GC wasn't adopted until Sept 3, 1752.

As a consequence, the Unix "cal" command defaults to
Sept 3, 1752:

# cal -3 9 1752

     August 1752         September 1752         October 1752   
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
                   1         1  2 14 15 16   1  2  3  4  5  6  7
 2  3  4  5  6  7  8  17 18 19 20 21 22 23   8  9 10 11 12 13 14
 9 10 11 12 13 14 15  24 25 26 27 28 29 30  15 16 17 18 19 20 21
16 17 18 19 20 21 22                        22 23 24 25 26 27 28
23 24 25 26 27 28 29                        29 30 31           
30 31 


The jump from Sept 2-14 is quite obvious.  The whole month only has
19 days!

However, we can instruct cal to use the "gregorian" or "iso"
option which causes cal to use the PROLEPTIC GREGORIAN CALENDAR (PGC).
The PGC changes over on Oct 15 1582 but all previous dates are a
backwards extrapolation of the GC.

The jump at Sept 3 1752 is gone:


# cal --reform iso -3 9 1752

     August 1752         September 1752         October 1752   
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
       1  2  3  4  5                  1  2   1  2  3  4  5  6  7
 6  7  8  9 10 11 12   3  4  5  6  7  8  9   8  9 10 11 12 13 14
13 14 15 16 17 18 19  10 11 12 13 14 15 16  15 16 17 18 19 20 21
20 21 22 23 24 25 26  17 18 19 20 21 22 23  22 23 24 25 26 27 28
27 28 29 30 31        24 25 26 27 28 29 30  29 30 31

But there is no jump at Oct 5 1582 either because all previous
dates are the GC extrapolated backwards:

# cal --reform iso -3 10 1582

   September 1582         October 1582          November 1582  
Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa  Su Mo Tu We Th Fr Sa
          1  2  3  4                  1  2      1  2  3  4  5  6
 5  6  7  8  9 10 11   3  4  5  6  7  8  9   7  8  9 10 11 12 13
12 13 14 15 16 17 18  10 11 12 13 14 15 16  14 15 16 17 18 19 20
19 20 21 22 23 24 25  17 18 19 20 21 22 23  21 22 23 24 25 26 27
26 27 28 29 30        24 25 26 27 28 29 30  28 29 30           
                      31

With LibreOffice Calc, there is no PGC.  We can observe the jump
at Oct 5, 1582 and all prior dates use the Julian calendar.

Links:

https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar

https://wiki.documentfoundation.org/Documentation/Calc_Functions/DATE


Of course, none of this is possible with that piece-of-shit OS known
as Microslop Winblows.  They only go forward and not backward.

Ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha!



--
Systemd: solving all the problems that you never knew you had.