From f3cc3dabe6db278308b157647f2ad3aa9dc8cf10 Mon Sep 17 00:00:00 2001
From: Kevin Ryde <user42@zip.com.au>
Date: Fri, 22 Aug 2003 22:28:53 +0000
Subject: [PATCH] (date-week-number): Correction, day of week starting week
 applied was off by one.

---
 srfi/srfi-19.scm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/srfi/srfi-19.scm b/srfi/srfi-19.scm
index 198ee5d04..fd4c9c112 100644
--- a/srfi/srfi-19.scm
+++ b/srfi/srfi-19.scm
@@ -821,8 +821,13 @@
     (modulo (- day-of-week-starting-week fdweek-day)
             7)))
 
+;; The "-1" here is a fix for the reference implementation, to make a new
+;; week start on the given day-of-week-starting-week.  date-year-day returns
+;; a day starting from 1 for 1st Jan.
+;;
 (define (date-week-number date day-of-week-starting-week)
   (quotient (- (date-year-day date)
+	       1
                (priv:days-before-first-week  date day-of-week-starting-week))
             7))