calendar-nth-named-day wrong for first Sunday in April, 2001

[Hugh L. Taylor]

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Hi,

Noticed this because emacs failed to adjust for daylight savings
time on my machine.  Running Win2K terminal server; no service packs.

Today is Monday, April 2, 2001.  If I understand the docs

(emacs-version)
"GNU Emacs 20.7.1 (i386-*-nt5.0.2195)
 of Tue Jun 13 2000 on buffy"

;today is Monday, April 2
; calculate the date of the first Sunday in April, 2001 -- should be
; Sunday April 1, 2001

(calendar-nth-named-day 1 0 4 2001 2)
(4 8 2001) % should be (4 1 2001)

(calendar-nth-named-day 1 1 4 2001 2)
(4 2 2001) % OK;