diff --git a/include/common/standard.h b/include/common/standard.h
index 9abdb0643..353d0b023 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -860,9 +860,6 @@ char *human_time(int t, short hz_div);
 
 extern const char *monthname[];
 
-/* numeric timezone (that is, the hour and minute offset from UTC) */
-char localtimezone[6];
-
 /* date2str_log: write a date in the format :
  * 	sprintf(str, "%02d/%s/%04d:%02d:%02d:%02d.%03d",
  *		tm.tm_mday, monthname[tm.tm_mon], tm.tm_year+1900,
@@ -873,6 +870,12 @@ char localtimezone[6];
  */
 char *date2str_log(char *dest, struct tm *tm, struct timeval *date, size_t size);
 
+/* Return the GMT offset for a specific local time.
+ * The string returned has the same format as returned by strftime(... "%z", tm).
+ * Offsets are kept in an internal cache for better performances.
+ */
+const char *get_gmt_offset(struct tm *tm);
+
 /* gmt2str_log: write a date in the format :
  * "%02d/%s/%04d:%02d:%02d:%02d +0000" without using snprintf
  * return a pointer to the last char written (\0) or
diff --git a/src/haproxy.c b/src/haproxy.c
index 4d38d2713..9842f3d3c 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -562,7 +562,6 @@ void init(int argc, char **argv)
 	struct wordlist *wl;
 	char *progname;
 	char *change_dir = NULL;
-	struct tm curtime;
 	struct proxy *px;
 
 	chunk_init(&trash, malloc(global.tune.bufsize), global.tune.bufsize);
@@ -588,15 +587,12 @@ void init(int argc, char **argv)
 	global.rlimit_memmax_all = HAPROXY_MEMMAX;
 #endif
 
+	tzset();
 	tv_update_date(-1,-1);
 	start_date = now;
 
 	srandom(now_ms - getpid());
 
-	/* Get the numeric timezone. */
-	get_localtime(start_date.tv_sec, &curtime);
-	strftime(localtimezone, 6, "%z", &curtime);
-
 	init_log();
 	signal_init();
 	if (init_acl() != 0)
diff --git a/src/log.c b/src/log.c
index 3e25bc79d..ab383531e 100644
--- a/src/log.c
+++ b/src/log.c
@@ -970,6 +970,7 @@ static char *update_log_hdr_rfc5424(const time_t time)
 {
 	static long tvsec;
 	static char *dataptr = NULL; /* backup of last end of header, NULL first time */
+	const char *gmt_offset;
 
 	if (unlikely(time != tvsec || dataptr == NULL)) {
 		/* this string is rebuild only once a second */
@@ -978,12 +979,13 @@ static char *update_log_hdr_rfc5424(const time_t time)
 
 		tvsec = time;
 		get_localtime(tvsec, &tm);
+		gmt_offset = get_gmt_offset(&tm);
 
 		hdr_len = snprintf(logheader_rfc5424, global.max_syslog_len,
 				   "<<<<>1 %4d-%02d-%02dT%02d:%02d:%02d%.3s:%.2s %s ",
 				   tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
 				   tm.tm_hour, tm.tm_min, tm.tm_sec,
-				   localtimezone, localtimezone+3,
+				   gmt_offset, gmt_offset+3,
 				   global.log_send_hostname ? global.log_send_hostname : hostname);
 		/* WARNING: depending upon implementations, snprintf may return
 		 * either -1 or the number of bytes that would be needed to store
diff --git a/src/standard.c b/src/standard.c
index 40727b0dd..e08795fd1 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -2552,6 +2552,35 @@ char *date2str_log(char *dst, struct tm *tm, struct timeval *date, size_t size)
 	return dst;
 }
 
+/* Return the GMT offset for a specific local time.
+ * The string returned has the same format as returned by strftime(... "%z", tm).
+ * Offsets are kept in an internal cache for better performances.
+ */
+const char *get_gmt_offset(struct tm *tm)
+{
+	/* Cache offsets from GMT (depending on whether DST is active or not) */
+	static char gmt_offsets[2][5+1] = { "", "" };
+
+    int old_isdst = tm->tm_isdst;
+	char *gmt_offset;
+
+    /* Pretend DST not active if its status is unknown, or strftime() will return an empty string for "%z" */
+    if (tm->tm_isdst < 0) {
+        tm->tm_isdst = 0;
+    }
+
+    /* Fetch the offset and initialize it if needed */
+    gmt_offset = gmt_offsets[tm->tm_isdst & 0x01];
+    if (unlikely(!*gmt_offset)) {
+        strftime(gmt_offset, 5+1, "%z", tm);
+    }
+
+    /* Restore previous DST flag */
+    tm->tm_isdst = old_isdst;
+
+    return gmt_offset;
+}
+
 /* gmt2str_log: write a date in the format :
  * "%02d/%s/%04d:%02d:%02d:%02d +0000" without using snprintf
  * return a pointer to the last char written (\0) or
@@ -2592,9 +2621,12 @@ char *gmt2str_log(char *dst, struct tm *tm, size_t size)
  */
 char *localdate2str_log(char *dst, struct tm *tm, size_t size)
 {
+	const char *gmt_offset;
 	if (size < 27) /* the size is fixed: 26 chars + \0 */
 		return NULL;
 
+	gmt_offset = get_gmt_offset(tm);
+
 	dst = utoa_pad((unsigned int)tm->tm_mday, dst, 3); // day
 	*dst++ = '/';
 	memcpy(dst, monthname[tm->tm_mon], 3); // month
@@ -2608,7 +2640,7 @@ char *localdate2str_log(char *dst, struct tm *tm, size_t size)
 	*dst++ = ':';
 	dst = utoa_pad((unsigned int)tm->tm_sec, dst, 3); // secondes
 	*dst++ = ' ';
-	memcpy(dst, localtimezone, 5); // timezone
+	memcpy(dst, gmt_offset, 5); // Offset from local time to GMT
 	dst += 5;
 	*dst = '\0';