scc

commit 56f71b43eec528d053af918f5ac199b5c38c7811
parent c82f5444f05f9b08b9f8e53b2fa43f640270f22a
Author: Roberto E. Vargas Caballero <k0ga@shike2.net>
Date:   Mon, 27 Apr 2026 16:20:18 +0200

time/libc: Consider the tz offset for dst rules

DST rules are specified in localtime calendar, and it means that we have
to consider the epoch offset for the timezone before calling _isdst().

Diffstat:
M
src/libc/time/localtime.c
 | 
10
++++------

1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/src/libc/time/localtime.c b/src/libc/time/localtime.c
@@ -7,17 +7,15 @@
 struct tm *
 localtime(const time_t *timep)
 {
-	time_t t;
 	int dst;
+	time_t t;
 	long off;
 	char *name;
 	struct tm *tm;
 
-	t = *timep;
-	tm = gmtime(&t);
 	_tzset();
-
-	if (_isdst(tm)) {
+	t = *timep - _timezone;
+	if (_isdst(gmtime(&t))) {
 		dst = 1;
 		off = _dstzone;
 		name = _tzname[1];
@@ -27,7 +25,7 @@ localtime(const time_t *timep)
 		name = _tzname[0];
 	}
 
-	t -= off;
+	t = *timep - off;
 	tm = gmtime(&t);
 	tm->tm_zone = name;
 	tm->tm_isdst = dst;