diff --git a/src/app/tests/TestTimeSyncDataProvider.cpp b/src/app/tests/TestTimeSyncDataProvider.cpp
index a4a658f330f83b..c7d28a0897a2cc 100644
--- a/src/app/tests/TestTimeSyncDataProvider.cpp
+++ b/src/app/tests/TestTimeSyncDataProvider.cpp
@@ -118,9 +118,9 @@ void TestTimeZoneStoreLoad(nlTestSuite * inSuite, void * inContext)
     char tzShort[]                             = "LA";
     char tzLong[]                              = "MunichOnTheLongRiverOfIsarInNiceSummerWeatherWithAugustinerBeer";
     char tzBerlin[]                            = "Berlin";
-    TimeSyncDataProvider::TimeZoneStore tzS[3] = { makeTimeZone(1, 1, tzShort, sizeof(tzShort)),
-                                                   makeTimeZone(2, 2, tzLong, sizeof(tzLong)),
-                                                   makeTimeZone(3, 3, tzBerlin, sizeof(tzBerlin)) };
+    TimeSyncDataProvider::TimeZoneStore tzS[3] = { makeTimeZone(1, 1, tzShort, sizeof(tzShort)-1),
+                                                   makeTimeZone(2, 2, tzLong, sizeof(tzLong)-1),
+                                                   makeTimeZone(3, 3, tzBerlin, sizeof(tzBerlin)-1) };
     TimeZoneList tzL(tzS);
     NL_TEST_ASSERT(inSuite, tzL.size() == 3);
     NL_TEST_ASSERT(inSuite, CHIP_NO_ERROR == timeSyncDataProv.StoreTimeZone(tzL));
@@ -141,7 +141,7 @@ void TestTimeZoneStoreLoad(nlTestSuite * inSuite, void * inContext)
         NL_TEST_ASSERT(inSuite, tz.offset == 1);
         NL_TEST_ASSERT(inSuite, tz.validAt == 1);
         NL_TEST_ASSERT(inSuite, tz.name.HasValue());
-        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 3);
+        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 2);
 
         tzL = tzL.SubSpan(1);
     }
@@ -152,7 +152,7 @@ void TestTimeZoneStoreLoad(nlTestSuite * inSuite, void * inContext)
         NL_TEST_ASSERT(inSuite, tz.offset == 2);
         NL_TEST_ASSERT(inSuite, tz.validAt == 2);
         NL_TEST_ASSERT(inSuite, tz.name.HasValue());
-        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 64);
+        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 63);
 
         tzL = tzL.SubSpan(1);
     }
@@ -163,7 +163,7 @@ void TestTimeZoneStoreLoad(nlTestSuite * inSuite, void * inContext)
         NL_TEST_ASSERT(inSuite, tz.offset == 3);
         NL_TEST_ASSERT(inSuite, tz.validAt == 3);
         NL_TEST_ASSERT(inSuite, tz.name.HasValue());
-        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 7);
+        NL_TEST_ASSERT(inSuite, tz.name.Value().size() == 6);
 
         tzL = tzL.SubSpan(1);
     }