--- a/src/os/unix/ngx_time.c
+++ b/src/os/unix/ngx_time.c
@@ -8,6 +8,50 @@
 #include <ngx_core.h>
 
 
+/*
+ * FreeBSD does not test /etc/localtime change, however, we can workaround it
+ * by calling tzset() with TZ and then without TZ to update timezone.
+ * The trick should work since FreeBSD 2.1.0.
+ *
+ * Linux does not test /etc/localtime change in localtime(),
+ * but may stat("/etc/localtime") several times in every strftime(),
+ * therefore we use it to update timezone.
+ *
+ * Solaris does not test /etc/TIMEZONE change too and no workaround available.
+ */
+
+void
+ngx_timezone_update(void)
+{
+#if (NGX_FREEBSD)
+
+    if (getenv("TZ")) {
+        return;
+    }
+
+    putenv("TZ=UTC");
+
+    tzset();
+
+    unsetenv("TZ");
+
+    tzset();
+
+#elif (NGX_LINUX)
+    time_t      s;
+    struct tm  *t;
+    char        buf[4];
+
+    s = time(0);
+
+    t = localtime(&s);
+
+    strftime(buf, 4, "%H", t);
+
+#endif
+}
+
+
 void
 ngx_localtime(time_t s, ngx_tm_t *tm)
 {