diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index d77dcc1..2c3dcc8 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -63,7 +63,7 @@
     tp = ngx_timeofday();
     tp->sec = 0;
 
-    ngx_time_update(0, 0);
+    ngx_time_update(0);
 
 
     log = old_cycle->log;
diff --git a/src/core/ngx_times.c b/src/core/ngx_times.c
index 3105beb..94993e2 100644
--- a/src/core/ngx_times.c
+++ b/src/core/ngx_times.c
@@ -28,6 +28,17 @@
 volatile ngx_str_t       ngx_cached_http_time;
 volatile ngx_str_t       ngx_cached_http_log_time;
 
+#if !(NGX_HAVE_GETTIMEZONE)
+
+/*
+ * locatime() and localtime_r() are not Async-Signal-Safe functions, therefore,
+ * if ngx_time_update() is called by signal handler, it uses the cached
+ * GMT offset value. Fortunately the value is changed only two times a year.
+ */
+
+static ngx_int_t         cached_gmtoff;
+#endif
+
 static ngx_time_t        cached_time[NGX_TIME_SLOTS];
 static u_char            cached_err_log_time[NGX_TIME_SLOTS]
                                     [sizeof("1970/09/28 12:00:00")];
@@ -50,15 +61,17 @@
 
     ngx_cached_time = &cached_time[0];
 
-    ngx_time_update(0, 0);
+    ngx_time_update(0);
 }
 
 
 void
-ngx_time_update(time_t sec, ngx_uint_t msec)
+ngx_time_update(ngx_uint_t use_cached_gmtoff)
 {
     u_char          *p0, *p1, *p2;
     ngx_tm_t         tm, gmt;
+    time_t           sec;
+    ngx_uint_t       msec;
     ngx_time_t      *tp;
     struct timeval   tv;
 
@@ -66,12 +79,10 @@
         return;
     }
 
-    if (sec == 0) {
-        ngx_gettimeofday(&tv);
+    ngx_gettimeofday(&tv);
 
-        sec = tv.tv_sec;
-        msec = tv.tv_usec / 1000;
-    }
+    sec = tv.tv_sec;
+    msec = tv.tv_usec / 1000;
 
     ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;
 
@@ -109,15 +120,23 @@
     tp->gmtoff = ngx_gettimezone();
     ngx_gmtime(sec + tp->gmtoff * 60, &tm);
 
-#elif (NGX_HAVE_GMTOFF)
-
-    ngx_localtime(sec, &tm);
-    tp->gmtoff = (ngx_int_t) (tm.ngx_tm_gmtoff / 60);
-
 #else
 
-    ngx_localtime(sec, &tm);
-    tp->gmtoff = ngx_timezone(tm.ngx_tm_isdst);
+    if (use_cached_gmtoff) {
+        ngx_gmtime(sec + cached_gmtoff * 60, &tm);
+
+    } else {
+        ngx_localtime(sec, &tm);
+
+#if (NGX_HAVE_GMTOFF)
+        cached_gmtoff = (ngx_int_t) (tm.ngx_tm_gmtoff / 60);
+#else
+        cached_gmtoff = ngx_timezone(tm.ngx_tm_isdst);
+#endif
+
+    }
+
+    tp->gmtoff = cached_gmtoff;
 
 #endif
 
diff --git a/src/core/ngx_times.h b/src/core/ngx_times.h
index 8363ca1..4259d17 100644
--- a/src/core/ngx_times.h
+++ b/src/core/ngx_times.h
@@ -20,7 +20,7 @@
 
 
 void ngx_time_init(void);
-void ngx_time_update(time_t sec, ngx_uint_t msec);
+void ngx_time_update(ngx_uint_t use_cached_gmtoff);
 u_char *ngx_http_time(u_char *buf, time_t t);
 u_char *ngx_http_cookie_time(u_char *buf, time_t t);
 void ngx_gmtime(time_t t, ngx_tm_t *tp);
diff --git a/src/event/modules/ngx_devpoll_module.c b/src/event/modules/ngx_devpoll_module.c
index f133b72..3655eb9 100644
--- a/src/event/modules/ngx_devpoll_module.c
+++ b/src/event/modules/ngx_devpoll_module.c
@@ -372,7 +372,7 @@
     err = (events == -1) ? ngx_errno : 0;
 
     if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     if (err) {
diff --git a/src/event/modules/ngx_epoll_module.c b/src/event/modules/ngx_epoll_module.c
index 3c1ca2a..838573a 100644
--- a/src/event/modules/ngx_epoll_module.c
+++ b/src/event/modules/ngx_epoll_module.c
@@ -532,7 +532,7 @@
     err = (events == -1) ? ngx_errno : 0;
 
     if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     if (err) {
diff --git a/src/event/modules/ngx_eventport_module.c b/src/event/modules/ngx_eventport_module.c
index 842d631..8abf4d3 100644
--- a/src/event/modules/ngx_eventport_module.c
+++ b/src/event/modules/ngx_eventport_module.c
@@ -405,7 +405,7 @@
     err = ngx_errno;
 
     if (flags & NGX_UPDATE_TIME) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     if (n == -1) {
@@ -439,7 +439,7 @@
     for (i = 0; i < events; i++) {
 
         if (event_list[i].portev_source == PORT_SOURCE_TIMER) {
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
             continue;
         }
 
diff --git a/src/event/modules/ngx_iocp_module.c b/src/event/modules/ngx_iocp_module.c
index 8375171..5ce8674 100644
--- a/src/event/modules/ngx_iocp_module.c
+++ b/src/event/modules/ngx_iocp_module.c
@@ -163,7 +163,7 @@
     for ( ;; ) {
         Sleep(timer);
 
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 #if 1
         ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0, "timer");
 #endif
@@ -258,7 +258,7 @@
     delta = ngx_current_msec;
 
     if (flags & NGX_UPDATE_TIME) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
diff --git a/src/event/modules/ngx_kqueue_module.c b/src/event/modules/ngx_kqueue_module.c
index b6dfa8f..e295d83 100644
--- a/src/event/modules/ngx_kqueue_module.c
+++ b/src/event/modules/ngx_kqueue_module.c
@@ -538,7 +538,7 @@
     err = (events == -1) ? ngx_errno : 0;
 
     if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
@@ -589,7 +589,7 @@
 #if (NGX_HAVE_TIMER_EVENT)
 
         if (event_list[i].filter == EVFILT_TIMER) {
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
             continue;
         }
 
diff --git a/src/event/modules/ngx_poll_module.c b/src/event/modules/ngx_poll_module.c
index 3b98c19..dc11d2e 100644
--- a/src/event/modules/ngx_poll_module.c
+++ b/src/event/modules/ngx_poll_module.c
@@ -263,7 +263,7 @@
     err = (ready == -1) ? ngx_errno : 0;
 
     if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
diff --git a/src/event/modules/ngx_rtsig_module.c b/src/event/modules/ngx_rtsig_module.c
index 926be0d..a8cf4ab 100644
--- a/src/event/modules/ngx_rtsig_module.c
+++ b/src/event/modules/ngx_rtsig_module.c
@@ -323,7 +323,7 @@
                        "rtsig signo:%d", signo);
 
         if (flags & NGX_UPDATE_TIME) {
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
 
         if (err == NGX_EAGAIN) {
@@ -349,7 +349,7 @@
                    signo, si.si_fd, si.si_band);
 
     if (flags & NGX_UPDATE_TIME) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     rtscf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_rtsig_module);
@@ -419,7 +419,7 @@
 
     } else if (signo == SIGALRM) {
 
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         return NGX_OK;
 
@@ -671,7 +671,7 @@
     }
 
     if (flags & NGX_UPDATE_TIME) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
diff --git a/src/event/modules/ngx_select_module.c b/src/event/modules/ngx_select_module.c
index 9f5b43b..0ca5fac 100644
--- a/src/event/modules/ngx_select_module.c
+++ b/src/event/modules/ngx_select_module.c
@@ -263,7 +263,7 @@
     err = (ready == -1) ? ngx_errno : 0;
 
     if (flags & NGX_UPDATE_TIME || ngx_event_timer_alarm) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
diff --git a/src/event/modules/ngx_win32_select_module.c b/src/event/modules/ngx_win32_select_module.c
index 8c22f39..8a3264d 100644
--- a/src/event/modules/ngx_win32_select_module.c
+++ b/src/event/modules/ngx_win32_select_module.c
@@ -269,7 +269,7 @@
     err = (ready == -1) ? ngx_socket_errno : 0;
 
     if (flags & NGX_UPDATE_TIME) {
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
     }
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index bd315ea..d24966f 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -1216,7 +1216,7 @@
 
     if (cache->files++ > 100) {
 
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         elapsed = ngx_abs((ngx_msec_int_t) (ngx_current_msec - cache->last));
 
@@ -1233,7 +1233,7 @@
 
             ngx_msleep(200);
 
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
 
         cache->last = ngx_current_msec;
diff --git a/src/os/unix/ngx_process.c b/src/os/unix/ngx_process.c
index 0d08349..4c41800 100644
--- a/src/os/unix/ngx_process.c
+++ b/src/os/unix/ngx_process.c
@@ -317,7 +317,7 @@
         }
     }
 
-    ngx_time_update(0, 0);
+    ngx_time_update(1);
 
     action = "";
 
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 06e020e..1804638 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -168,7 +168,7 @@
 
         sigsuspend(&set);
 
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                        "wake up, sigio %i", sigio);
@@ -1342,7 +1342,7 @@
 
             next = (n <= next) ? n : next;
 
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
     }
 
@@ -1372,7 +1372,7 @@
 
         if (path[i]->loader) {
             path[i]->loader(path[i]->data);
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
     }
 
diff --git a/src/os/win32/ngx_process.c b/src/os/win32/ngx_process.c
index e57adb4..08d9c0e 100644
--- a/src/os/win32/ngx_process.c
+++ b/src/os/win32/ngx_process.c
@@ -85,7 +85,7 @@
 
     rc = WaitForMultipleObjects(2, events, 0, 5000);
 
-    ngx_time_update(0, 0);
+    ngx_time_update(0);
 
     ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                    "WaitForMultipleObjects: %ul", rc);
diff --git a/src/os/win32/ngx_process_cycle.c b/src/os/win32/ngx_process_cycle.c
index e3b513a..e4e92b8 100644
--- a/src/os/win32/ngx_process_cycle.c
+++ b/src/os/win32/ngx_process_cycle.c
@@ -140,7 +140,7 @@
         ev = WaitForMultipleObjects(nev, events, 0, timeout);
 
         err = ngx_errno;
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                        "master WaitForMultipleObjects: %ul", ev);
@@ -679,7 +679,7 @@
         ev = WaitForMultipleObjects(3, events, 0, INFINITE);
 
         err = ngx_errno;
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
                        "worker WaitForMultipleObjects: %ul", ev);
@@ -738,7 +738,7 @@
         ev = WaitForMultipleObjects(nev, events, 0, INFINITE);
 
         err = ngx_errno;
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
                        "worker exit WaitForMultipleObjects: %ul", ev);
@@ -907,7 +907,7 @@
         ev = WaitForMultipleObjects(2, events, 0, INFINITE);
 
         err = ngx_errno;
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, 0,
                        "cache manager WaitForMultipleObjects: %ul", ev);
@@ -968,7 +968,7 @@
 
             next = (n <= next) ? n : next;
 
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
     }
 
@@ -980,7 +980,7 @@
 
     if (ev != WAIT_TIMEOUT) {
 
-        ngx_time_update(0, 0);
+        ngx_time_update(0);
 
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
                        "cache manager WaitForSingleObject: %ul", ev);
@@ -1008,7 +1008,7 @@
 
         if (path[i]->loader) {
             path[i]->loader(path[i]->data);
-            ngx_time_update(0, 0);
+            ngx_time_update(0);
         }
     }