From: Dan Harkless <dan@harkless.org>
Date: Tue, 14 Mar 2000 05:24:57 +0000 (+0000)
Subject: Applied Simon Burge <simonb@thistledown.com.au>'s dtime.c patch:
X-Git-Tag: nmh-1_0~63
X-Git-Url: http://git.marmaro.de/?a=commitdiff_plain;h=79fcc0e0c68cd0cb8b9edc7c9db5eeaa2358d756;p=mmh

Applied Simon Burge <simonb@thistledown.com.au>'s dtime.c patch:

  There's a wrap-around problem that affects the implementation of Zeller's
  congruence in dtime.c.  This causes the day-of-week calculations to fail for
  dates after Feb 29, 2000 (probably up until some year far in the future).
---

diff --git a/ChangeLog b/ChangeLog
index ba38c6b..0410e49 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,4 @@
-Mon Mar 13 21:10:16 2000 Dan Harkless <dan-nmh@dilvish.speed.net>
+Mon Mar 13 21:32:00 2000 Dan Harkless <dan-nmh@dilvish.speed.net>
 
 	* Applied Sullivan N. Beck <sbeck@cise.ufl.edu>'s mhshow-suffix patch:
 
@@ -23,6 +23,13 @@ Mon Mar 13 21:10:16 2000 Dan Harkless <dan-nmh@dilvish.speed.net>
 	mailbox called, for instance, "dan-nmh" (where username was "dan"
 	and $USERNAME_EXTENSION was "-nmh").
 		
+	* Applied Simon Burge <simonb@thistledown.com.au>'s dtime.c patch:
+	
+	    There's a wrap-around problem that affects the implementation
+	    of Zeller's congruence in dtime.c.  This causes the day-of-week
+	    calculations to fail for dates after Feb 29, 2000 (probably up
+	    until some year far in the future).
+
 Mon Mar 06 12:20:20 2000 Dan Harkless <dan-nmh@dilvish.speed.net>
 
 	* Applied Neil W Rickert <rickert+nmh@cs.niu.edu>'s msh.c patch:
diff --git a/zotnet/tws/dtime.c b/zotnet/tws/dtime.c
index bbfccf0..adf153b 100644
--- a/zotnet/tws/dtime.c
+++ b/zotnet/tws/dtime.c
@@ -460,6 +460,8 @@ set_dotw (struct tws *tw)
     tw->tw_wday =
 	((26 * month - 2) / 10 + day + year + year / 4
 	    - 3 * century / 4 + 1) % 7;
+    if (tw->tw_wday < 0)
+	tw->tw_wday += 7;
 
     tw->tw_flags &= ~TW_SDAY, tw->tw_flags |= TW_SIMP;
 }