diff --git a/chrony.texi b/chrony.texi
index 9b75eff..b09da92 100644
--- a/chrony.texi
+++ b/chrony.texi
@@ -1183,6 +1183,7 @@ directives can occur in any order in the file.
 * include directive::           Include a configuration file
 * initstepslew directive::      Trim the system clock on boot-up.
 * keyfile directive::           Specify location of file containing keys
+* leapsectz directive::         Read leap second data from tz database
 * linux_hz directive::          Define a non-standard value of the kernel HZ constant
 * linux_freq_scale directive::  Define a non-standard value to compensate the kernel frequency bias
 * local directive::             Allow unsynchronised machine to act as server
@@ -1744,6 +1745,25 @@ prefix.
 
 The ID for the chronyc authentication key is specified with the
 commandkey command (see earlier).
+@c }}}
+@c {{{ leapsectz
+@node leapsectz directive
+@subsection leapsectz
+This directive is used to set the name of the timezone in the system
+tz database which @code{chronyd} can use to find out when will the
+next leap second occur.  It will periodically check if the times
+23:59:59 and 23:59:60 are valid on Jun 30 and Dec 31 in the timezone.
+This is mainly useful with reference clocks which don't provide the
+leap second information.  It is not necessary to restart
+@code{chronyd} if the tz database is updated with a new leap second at
+least 12 hours before the event.
+
+An example of the command is
+
+@example
+leapsectz right/UTC
+@end example
+
 @c }}}
 @c {{{ local
 @node local directive
@@ -1894,9 +1914,9 @@ expressed in UTC, not the local time zone.
 IP address of server/peer from which measurement comes [158.152.1.76]
 @item
 Leap status (@code{N} means normal, @code{+} means that the last minute
-of today has 61 seconds, @code{-} means that the last minute of the day
-has 59 seconds, @code{?} means the remote computer is not currently
-synchronised.) [N]
+of the current month has 61 seconds, @code{-} means that the last minute
+of the month has 59 seconds, @code{?} means the remote computer is not
+currently synchronised.) [N]
 @item
 Stratum of remote computer. [2]
 @item
@@ -2110,8 +2130,8 @@ Sequence number of driver poll within one polling interval for raw
 samples, or @code{-} for filtered samples. [7]
 @item
 Leap status (@code{N} means normal, @code{+} means that the last minute
-of today has 61 seconds, @code{-} means that the last minute of the day
-has 59 seconds). [N]
+of the current month has 61 seconds, @code{-} means that the last minute
+of the month has 59 seconds). [N]
 @item
 Flag indicating whether the sample comes from PPS source. (1 for yes,
 0 for no, or @code{-} for filtered sample). [1]
diff --git a/conf.c b/conf.c
index bbd890c..460b42f 100644
--- a/conf.c
+++ b/conf.c
@@ -112,6 +112,7 @@ static void parse_sched_priority(const char *);
 static void parse_lockall(const char *);
 static void parse_tempcomp(const char *);
 static void parse_include(const char *);
+static void parse_leapsectz(const char *);
 
 /* ================================================== */
 /* Configuration variables */
@@ -224,6 +225,9 @@ static double linux_freq_scale;
 static int sched_priority = 0;
 static int lock_memory = 0;
 
+/* Name of a system timezone containing leap seconds occuring at midnight */
+static char *leapsec_tz = NULL;
+
 /* ================================================== */
 
 typedef struct {
@@ -276,6 +280,7 @@ static const Command commands[] = {
   {"reselectdist", 12, parse_reselectdist},
   {"stratumweight", 13, parse_stratumweight},
   {"include", 7, parse_include},
+  {"leapsectz", 9, parse_leapsectz},
   {"linux_hz", 8, parse_linux_hz},
   {"linux_freq_scale", 16, parse_linux_freq_scale},
   {"sched_priority", 14, parse_sched_priority},
@@ -1282,6 +1287,16 @@ parse_include(const char *line)
 
 /* ================================================== */
 
+static void
+parse_leapsectz(const char *line)
+{
+  /* This must allocate enough space! */
+  leapsec_tz = MallocArray(char, 1 + strlen(line));
+  sscanf(line, "%s", leapsec_tz);
+}
+
+/* ================================================== */
+
 static void
 parse_linux_hz(const char *line)
 {
@@ -1707,6 +1722,14 @@ CNF_GetPidFile(void)
 
 /* ================================================== */
 
+char *
+CNF_GetLeapSecTimezone(void)
+{
+  return leapsec_tz;
+}
+
+/* ================================================== */
+
 void
 CNF_GetLinuxHz(int *set, int *hz)
 {
diff --git a/conf.h b/conf.h
index 7f0f6b3..15d24d7 100644
--- a/conf.h
+++ b/conf.h
@@ -69,6 +69,7 @@ extern void CNF_GetFallbackDrifts(int *min, int *max);
 extern void CNF_GetBindAddress(int family, IPAddr *addr);
 extern void CNF_GetBindCommandAddress(int family, IPAddr *addr);
 extern char *CNF_GetPidFile(void);
+extern char *CNF_GetLeapSecTimezone(void);
 extern void CNF_GetLinuxHz(int *set, int *hz);
 extern void CNF_GetLinuxFreqScale(int *set, double *freq_scale);
 
diff --git a/reference.c b/reference.c
index 7bf8ec7..0310d20 100644
--- a/reference.c
+++ b/reference.c
@@ -89,6 +89,11 @@ static double drift_file_age;
 
 static void update_drift_file(double, double);
 
+/* Name of a system timezone containing leap seconds occuring at midnight */
+static char *leap_tzname;
+static time_t last_tz_leap_check;
+static NTP_Leap tz_leap;
+
 /* ================================================== */
 
 static LOG_FileID logfileid;
@@ -196,6 +201,8 @@ REF_Initialise(void)
 
   enable_local_stratum = CNF_AllowLocalReference(&local_stratum);
 
+  leap_tzname = CNF_GetLeapSecTimezone();
+
   CNF_GetMakeStep(&make_step_limit, &make_step_threshold);
   CNF_GetMaxChange(&max_offset_delay, &max_offset_ignore, &max_offset);
   CNF_GetLogChange(&do_log_change, &log_change_threshold);
@@ -526,20 +533,82 @@ is_offset_ok(double offset)
 
 /* ================================================== */
 
-static void
-update_leap_status(NTP_Leap leap)
+static NTP_Leap
+get_tz_leap(time_t when)
+{
+  struct tm stm;
+  time_t t;
+  char *tz_env, tz_orig[128];
+
+  /* Do this check at most twice a day */
+  when = when / (12 * 3600) * (12 * 3600);
+  if (last_tz_leap_check == when)
+      return tz_leap;
+
+  last_tz_leap_check = when;
+  tz_leap = LEAP_Normal;
+
+  stm = *gmtime(&when);
+
+  /* Check for leap second only in the latter half of June and December */
+  if (stm.tm_mon == 5 && stm.tm_mday > 14)
+    stm.tm_mday = 30;
+  else if (stm.tm_mon == 11 && stm.tm_mday > 14)
+    stm.tm_mday = 31;
+  else
+    return tz_leap;
+
+  /* Temporarily switch to the timezone containing leap seconds */
+  tz_env = getenv("TZ");
+  if (tz_env) {
+    if (strlen(tz_env) >= sizeof (tz_orig))
+      return tz_leap;
+    strcpy(tz_orig, tz_env);
+  }
+  setenv("TZ", leap_tzname, 1);
+  tzset();
+
+  /* Set the time to 23:59:60 and see how it overflows in mktime() */
+  stm.tm_sec = 60;
+  stm.tm_min = 59;
+  stm.tm_hour = 23;
+
+  t = mktime(&stm);
+
+  if (tz_env)
+    setenv("TZ", tz_orig, 1);
+  else
+    unsetenv("TZ");
+  tzset();
+
+  if (t == -1)
+    return tz_leap;
+
+  if (stm.tm_sec == 60)
+    tz_leap = LEAP_InsertSecond;
+  else if (stm.tm_sec == 1)
+    tz_leap = LEAP_DeleteSecond;
+
+  return tz_leap;
+}
+
+/* ================================================== */
+
+static void
+update_leap_status(NTP_Leap leap, time_t now)
 {
-  time_t now;
   struct tm stm;
   int leap_sec;
 
   leap_sec = 0;
 
+  if (leap_tzname && now && leap == LEAP_Normal)
+    leap = get_tz_leap(now);
+
   if (leap == LEAP_InsertSecond || leap == LEAP_DeleteSecond) {
     /* Insert/delete leap second only on June 30 or December 31
        and in other months ignore the leap status completely */
 
-    now = time(NULL);
     stm = *gmtime(&now);
 
     if (stm.tm_mon != 5 && stm.tm_mon != 11) {
@@ -600,7 +669,7 @@ REF_SetReference(int stratum,
   double update_interval;
   double elapsed;
   double correction_rate;
-  struct timeval now;
+  struct timeval now, raw_now;
 
   assert(initialised);
 
@@ -628,7 +697,9 @@ REF_SetReference(int stratum,
     }
   }
     
-  LCL_ReadCookedTime(&now, NULL);
+  LCL_ReadRawTime(&raw_now);
+  LCL_CookTime(&raw_now, &now, NULL);
+
   UTI_DiffTimevalsToDouble(&elapsed, &now, ref_time);
   our_offset = offset + elapsed * frequency;
 
@@ -646,7 +717,7 @@ REF_SetReference(int stratum,
   our_root_delay = root_delay;
   our_root_dispersion = root_dispersion;
 
-  update_leap_status(leap);
+  update_leap_status(leap, raw_now.tv_sec);
 
   if (last_ref_update.tv_sec) {
     UTI_DiffTimevalsToDouble(&update_interval, &now, &last_ref_update);
@@ -827,7 +898,7 @@ REF_SetUnsynchronised(void)
 
   are_we_synchronised = 0;
 
-  update_leap_status(LEAP_Unsynchronised);
+  update_leap_status(LEAP_Unsynchronised, 0);
 }
 
 /* ================================================== */