Day of week question

Do to a bug in pgtypeslin I've been experimenting with the day of week
stuff a little bit and I found that we do not agree with the output of
the cal command on older dates. I have no idea which one is correct:

mm=# select to_char('1000/01/01'::date,'D');
to_char
---------
4
(1 row)

Thus we believe 1000/1/1 is a Wednesday. cal says:

Januar 1000
So Mo Di Mi Do Fr Sa
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

Thus 1000/1/1 is a Monday. Is this a bug in cal? Or do we produce the
wrong output? Or do I simply misread the output?

Michael
--
Michael Meskes
Email: Michael at Fam-Meskes dot De
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