1 files changed, 34 insertions, 0 deletions
diff --git a/source4/lib/time.c b/source4/lib/time.c
index 61e92b8c00..5de9046c8d 100644
--- a/source4/lib/time.c
+++ b/source4/lib/time.c
@@ -594,3 +594,37 @@ NTTIME timeval_to_nttime(const struct timeval *tv)
 	return 10*(tv->tv_usec + 
 		  ((TIME_FIXUP_CONSTANT + (uint64_t)tv->tv_sec) * 1000000));
 }
+
+/*******************************************************************
+yield the difference between *A and *B, in seconds, ignoring leap seconds
+********************************************************************/
+static int tm_diff(struct tm *a, struct tm *b)
+{
+	int ay = a->tm_year + (1900 - 1);
+	int by = b->tm_year + (1900 - 1);
+	int intervening_leap_days =
+		(ay/4 - by/4) - (ay/100 - by/100) + (ay/400 - by/400);
+	int years = ay - by;
+	int days = 365*years + intervening_leap_days + (a->tm_yday - b->tm_yday);
+	int hours = 24*days + (a->tm_hour - b->tm_hour);
+	int minutes = 60*hours + (a->tm_min - b->tm_min);
+	int seconds = 60*minutes + (a->tm_sec - b->tm_sec);
+
+	return seconds;
+}
+
+/*******************************************************************
+  return the UTC offset in seconds west of UTC, or 0 if it cannot be determined
+  ******************************************************************/
+int get_time_zone(time_t t)
+{
+	struct tm *tm = gmtime(&t);
+	struct tm tm_utc;
+	if (!tm)
+		return 0;
+	tm_utc = *tm;
+	tm = localtime(&t);
+	if (!tm)
+		return 0;
+	return tm_diff(&tm_utc,tm);
+}