diff --git a/src/libCom/test/Makefile b/src/libCom/test/Makefile
index e8e94a3e6..7e1b5a020 100644
--- a/src/libCom/test/Makefile
+++ b/src/libCom/test/Makefile
@@ -68,6 +68,10 @@ epicsTimeTest_SRCS += epicsTimeTest.cpp
 testHarness_SRCS += epicsTimeTest.cpp
 TESTS += epicsTimeTest
 
+TESTPROD_HOST += epicsTimeZoneTest
+epicsTimeZoneTest_SRCS += epicsTimeZoneTest.c
+TESTS += epicsTimeZoneTest
+
 TESTPROD_HOST += epicsThreadTest
 epicsThreadTest_SRCS += epicsThreadTest.cpp
 testHarness_SRCS += epicsThreadTest.cpp
diff --git a/src/libCom/test/epicsTimeZoneTest.c b/src/libCom/test/epicsTimeZoneTest.c
new file mode 100644
index 000000000..dd12b1acf
--- /dev/null
+++ b/src/libCom/test/epicsTimeZoneTest.c
@@ -0,0 +1,117 @@
+/*************************************************************************\
+* Copyright (c) 2015 Michael Davidsaver
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#include <stdio.h>
+
+#include "envDefs.h"
+#include "epicsTime.h"
+#include "epicsUnitTest.h"
+
+#include "testMain.h"
+
+#if defined(_WIN32)
+#  define tzset _tzset
+#endif
+
+static
+void setTZ(const char *base, const char *dst, int offset)
+{
+    char tz[20];
+    if(offset!=0 || dst)
+        sprintf(tz, "%s%d%s", base, offset/3600, dst);
+    else
+        sprintf(tz, "%s", base);
+    testDiag("TZ=\"%s\"", tz);
+
+    epicsEnvSet("TZ", tz);
+    tzset();
+}
+
+static
+void test_localtime(time_t T, int sec, int min, int hour,
+                    int mday, int mon, int year,
+                    int wday, int yday, int isdst)
+{
+    struct tm B;
+    testDiag("test_localtime(%ld, ...)", (long)T);
+    if(epicsTime_localtime(&T, &B)!=epicsTimeOK) {
+        testFail("epicsTime_localtime() error");
+        testSkip(9, "epicsTime_localtime() failed");
+    } else {
+        B.tm_year += 1900; /* for readability */
+        testPass("epicsTime_localtime() success");
+#define TEST(FLD) testOk(B.tm_##FLD==FLD, "%s %d==%d", #FLD, B.tm_##FLD, FLD)
+        TEST(sec);
+        TEST(min);
+        TEST(hour);
+        TEST(mday);
+        TEST(mon);
+        TEST(year);
+        TEST(wday);
+        TEST(yday);
+        TEST(isdst);
+#undef TEST
+    }
+}
+
+static
+void test_gmtime(time_t T, int sec, int min, int hour,
+                    int mday, int mon, int year,
+                    int wday, int yday, int isdst)
+{
+    struct tm B;
+    testDiag("test_gmtime(%ld, ...)", (long)T);
+    if(epicsTime_gmtime(&T, &B)!=epicsTimeOK) {
+        testFail("epicsTime_localtime() error");
+        testSkip(9, "epicsTime_localtime() failed");
+    } else {
+        B.tm_year += 1900; /* for readability */
+        testPass("epicsTime_localtime() success");
+#define TEST(FLD) testOk(B.tm_##FLD==FLD, "%s %d==%d", #FLD, B.tm_##FLD, FLD)
+        TEST(sec);
+        TEST(min);
+        TEST(hour);
+        TEST(mday);
+        TEST(mon);
+        TEST(year);
+        TEST(wday);
+        TEST(yday);
+        TEST(isdst);
+#undef TEST
+    }
+}
+
+MAIN(epicsTimeZoneTest)
+{
+    testPlan(80);
+    /* 1445259616
+     *  Mon Oct 19 09:00:16 2015 EDT
+     *  Mon Oct 19 08:00:16 2015 CDT
+     *  Mon Oct 19 13:00:16 2015 UTC
+     */
+    testDiag("POSIX 1445259616");
+    setTZ("EST", "EDT", 5*3600);
+    test_localtime(1445259616ul, 16, 0, 9, 19, 9, 2015, 1, 291, 1);
+    setTZ("CST", "CDT", 6*3600);
+    test_localtime(1445259616ul, 16, 0, 8, 19, 9, 2015, 1, 291, 1);
+    setTZ("UTC", NULL, 0);
+    test_localtime(1445259616ul, 16, 0, 13, 19, 9, 2015, 1, 291, 0);
+    test_gmtime(1445259616ul, 16, 0, 13, 19, 9, 2015, 1, 291, 0);
+    /* 1421244931
+     *  Wed Jan 14 09:15:31 2015 EST
+     *  Wed Jan 14 08:15:31 2015 CST
+     *  Wed Jan 14 14:15:31 2015 UTC
+     */
+    testDiag("POSIX 1421244931");
+    setTZ("EST", "EDT", 5*3600);
+    test_localtime(1421244931ul, 31, 15, 9, 14, 0, 2015, 3, 13, 0);
+    setTZ("CST", "CDT", 6*3600);
+    test_localtime(1421244931ul, 31, 15, 8, 14, 0, 2015, 3, 13, 0);
+    setTZ("UTC", NULL, 0);
+    test_localtime(1421244931ul, 31, 15, 14, 14, 0, 2015, 3, 13, 0);
+    test_gmtime(1421244931ul, 31, 15, 14, 14, 0, 2015, 3, 13, 0);
+    return testDone();
+}