diff --git a/exercises/practice/gigasecond/.meta/tests.toml b/exercises/practice/gigasecond/.meta/tests.toml
index 18672327..7f75cf5e 100644
--- a/exercises/practice/gigasecond/.meta/tests.toml
+++ b/exercises/practice/gigasecond/.meta/tests.toml
@@ -1,6 +1,13 @@
-# This is an auto-generated file. Regular comments will be removed when this
-# file is regenerated. Regenerating will not touch any manually added keys,
-# so comments can be added in a "comment" key.
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
 
 [92fbe71c-ea52-4fac-bd77-be38023cacf7]
 description = "date only specification of time"
@@ -16,3 +23,7 @@ description = "full time specified"
 
 [09d4e30e-728a-4b52-9005-be44a58d9eba]
 description = "full time with day roll-over"
+
+[fcec307c-7529-49ab-b0fe-20309197618a]
+description = "does not mutate the input"
+include = false
diff --git a/exercises/practice/gigasecond/gigasecond_test.cpp b/exercises/practice/gigasecond/gigasecond_test.cpp
index 7dd448a8..6dfd769a 100644
--- a/exercises/practice/gigasecond/gigasecond_test.cpp
+++ b/exercises/practice/gigasecond/gigasecond_test.cpp
@@ -14,42 +14,46 @@
 
 using namespace boost::posix_time;
 
-TEST_CASE("test_1")
-{
-    const ptime actual = gigasecond::advance(time_from_string("2011-04-25 00:00:00"));
+TEST_CASE("date only specification of time",
+          "[92fbe71c-ea52-4fac-bd77-be38023cacf7]") {
+    const ptime actual =
+        gigasecond::advance(time_from_string("2011-04-25 00:00:00"));
 
     const ptime expected(time_from_string("2043-01-01 01:46:40"));
     REQUIRE(expected == actual);
 }
 
 #if defined(EXERCISM_RUN_ALL_TESTS)
-TEST_CASE("test_2")
-{
-    const auto actual = gigasecond::advance(time_from_string("1977-06-13 00:00:00"));
+TEST_CASE("second test for date only specification of time",
+          "[6d86dd16-6f7a-47be-9e58-bb9fb2ae1433]") {
+    const auto actual =
+        gigasecond::advance(time_from_string("1977-06-13 00:00:00"));
 
     const ptime expected(time_from_string("2009-02-19 01:46:40"));
     REQUIRE(expected == actual);
 }
 
-TEST_CASE("test_3")
-{
-    const auto actual = gigasecond::advance(time_from_string("1959-07-19 00:00:00"));
+TEST_CASE("third test for date only specification of time",
+          "[77eb8502-2bca-4d92-89d9-7b39ace28dd5]") {
+    const auto actual =
+        gigasecond::advance(time_from_string("1959-07-19 00:00:00"));
 
     const ptime expected(time_from_string("1991-03-27 01:46:40"));
     REQUIRE(expected == actual);
 }
 
-TEST_CASE("test_4")
-{
-    const auto actual = gigasecond::advance(time_from_string("2015-01-24 22:00:00"));
+TEST_CASE("full time specified", "[c9d89a7d-06f8-4e28-a305-64f1b2abc693]") {
+    const auto actual =
+        gigasecond::advance(time_from_string("2015-01-24 22:00:00"));
 
     const ptime expected(time_from_string("2046-10-02 23:46:40"));
     REQUIRE(expected == actual);
 }
 
-TEST_CASE("test_5")
-{
-    const auto actual = gigasecond::advance(time_from_string("2015-01-24 23:59:59"));
+TEST_CASE("full time with day roll-over",
+          "[09d4e30e-728a-4b52-9005-be44a58d9eba]") {
+    const auto actual =
+        gigasecond::advance(time_from_string("2015-01-24 23:59:59"));
 
     const ptime expected(time_from_string("2046-10-03 01:46:39"));
     REQUIRE(expected == actual);