diff --git a/test/intl402/Temporal/PlainDate/prototype/add/basic-chinese.js b/test/intl402/Temporal/PlainDate/prototype/add/basic-chinese.js
index a2cad14558..b4627387ff 100644
--- a/test/intl402/Temporal/PlainDate/prototype/add/basic-chinese.js
+++ b/test/intl402/Temporal/PlainDate/prototype/add/basic-chinese.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.PlainDate.from({ year: 2018, monthCode: "M02", day: 1, calendar }, options);
 const date202302 = Temporal.PlainDate.from({ year: 2023, monthCode: "M02", day: 29, calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDate(
   2001, 6, "M05", 18, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDate(
+  date199712.add(years3months6days17n),
+  1994, 5, "M05", 14, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,12 +81,14 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 const durations = [
   months1,
   months1n,
   months4,
   months4n,
-  months6
+  months6,
+  months6n,
 ];
 
 const date201901 = Temporal.PlainDate.from({ year: 2019, monthCode: "M01", day: 1, calendar }, options);
@@ -141,6 +149,11 @@ TemporalHelpers.assertPlainDate(
   2001, 6, "M05", 1, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDate(
+  date200012.add(months6n),
+  2000, 6, "M06", 1, "Subtracting 6 months, with result in same year"
+);
+
 for (var duration of durations) {
   for (var start of dates) {
     const end = start.add(duration);
@@ -183,6 +196,7 @@ for (var duration of durations) {
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 1, calendar }, options);
 const date20000101 = Temporal.PlainDate.from({ year: 2000, month: 1, day: 1, calendar }, options);
@@ -212,11 +226,17 @@ TemporalHelpers.assertPlainDate(
   2000, 10, "M10", 16, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDate(
+  date20000101.add(weeks40n),
+  1999, 3, "M03", 16, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 29, calendar }, options);
 
@@ -254,3 +274,8 @@ TemporalHelpers.assertPlainDate(
   date20000101.add(days200),
   2000, 7, "M07", 24, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDate(
+  date20000101.add(days200n),
+  1999, 6, "M06", 8, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/PlainDate/prototype/add/basic-dangi.js b/test/intl402/Temporal/PlainDate/prototype/add/basic-dangi.js
index c209dee227..e2b0692d9e 100644
--- a/test/intl402/Temporal/PlainDate/prototype/add/basic-dangi.js
+++ b/test/intl402/Temporal/PlainDate/prototype/add/basic-dangi.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.PlainDate.from({ year: 2018, monthCode: "M02", day: 1, calendar }, options);
 const date202302 = Temporal.PlainDate.from({ year: 2023, monthCode: "M02", day: 29, calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDate(
   2001, 6, "M05", 18, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDate(
+  date199712.add(years3months6days17n),
+  1994, 5, "M05", 14, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,12 +81,14 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 const durations = [
   months1,
   months1n,
   months4,
   months4n,
-  months6
+  months6,
+  months6n,
 ];
 
 const date201901 = Temporal.PlainDate.from({ year: 2019, monthCode: "M01", day: 1, calendar }, options);
@@ -141,6 +149,11 @@ TemporalHelpers.assertPlainDate(
   2001, 6, "M05", 1, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDate(
+  date200012.add(months6n),
+  2000, 6, "M06", 1, "Subtracting 6 months, with result in same year"
+);
+
 for (var duration of durations) {
   for (var start of dates) {
     const end = start.add(duration);
@@ -183,6 +196,7 @@ for (var duration of durations) {
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 1, calendar }, options);
 const date20000101 = Temporal.PlainDate.from({ year: 2000, month: 1, day: 1, calendar }, options);
@@ -212,11 +226,17 @@ TemporalHelpers.assertPlainDate(
   2000, 10, "M10", 16, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDate(
+  date20000101.add(weeks40n),
+  1999, 3, "M03", 16, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 29, calendar }, options);
 
@@ -254,3 +274,8 @@ TemporalHelpers.assertPlainDate(
   date20000101.add(days200),
   2000, 7, "M07", 24, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDate(
+  date20000101.add(days200n),
+  1999, 6, "M06", 8, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/PlainDate/prototype/subtract/basic-chinese.js b/test/intl402/Temporal/PlainDate/prototype/subtract/basic-chinese.js
index 3379061f0e..2a9b02732a 100644
--- a/test/intl402/Temporal/PlainDate/prototype/subtract/basic-chinese.js
+++ b/test/intl402/Temporal/PlainDate/prototype/subtract/basic-chinese.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.PlainDate.from({ year: 2018, monthCode: "M02", day: 1, calendar }, options);
 const date202302 = Temporal.PlainDate.from({ year: 2023, monthCode: "M02", day: 29, calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date199712.subtract(years3months6days17),
+  2001, 6, "M05", 18, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDate(
+  date199712.subtract(years3months6days17n),
   1994, 5, "M05", 14, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,13 +80,15 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 const durations = [
   months1,
   months1n,
   months4,
   months4n,
-  months6
+  months6,
+  months6n,
 ];
 
 const date201901 = Temporal.PlainDate.from({ year: 2019, monthCode: "M01", day: 1, calendar }, options);
@@ -138,6 +146,11 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date200012.subtract(months6),
+  2001, 6, "M05", 1, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDate(
+  date200012.subtract(months6n),
   2000, 6, "M06", 1, "Subtracting 6 months, with result in same year"
 );
 
@@ -182,7 +195,8 @@ for (var duration of durations) {
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 1, calendar }, options);
 const date20000101 = Temporal.PlainDate.from({ year: 2000, month: 1, day: 1, calendar }, options);
@@ -209,6 +223,11 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date20000101.subtract(weeks40),
+  2000, 10, "M10", 16, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDate(
+  date20000101.subtract(weeks40n),
   1999, 3, "M03", 16, "subtract 40 weeks, ending in previous year"
 );
 
@@ -216,7 +235,8 @@ TemporalHelpers.assertPlainDate(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 29, calendar }, options);
 
@@ -252,5 +272,10 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date20000101.subtract(days200),
+  2000, 7, "M07", 24, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDate(
+  date20000101.subtract(days200n),
   1999, 6, "M06", 8, "subtract 200 days, ending in previous year"
 );
diff --git a/test/intl402/Temporal/PlainDate/prototype/subtract/basic-dangi.js b/test/intl402/Temporal/PlainDate/prototype/subtract/basic-dangi.js
index f0d6d50264..421b20db71 100644
--- a/test/intl402/Temporal/PlainDate/prototype/subtract/basic-dangi.js
+++ b/test/intl402/Temporal/PlainDate/prototype/subtract/basic-dangi.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.PlainDate.from({ year: 2018, monthCode: "M02", day: 1, calendar }, options);
 const date202302 = Temporal.PlainDate.from({ year: 2023, monthCode: "M02", day: 29, calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date199712.subtract(years3months6days17),
+  2001, 6, "M05", 18, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDate(
+  date199712.subtract(years3months6days17n),
   1994, 5, "M05", 14, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,13 +80,15 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 const durations = [
   months1,
   months1n,
   months4,
   months4n,
-  months6
+  months6,
+  months6n,
 ];
 
 const date201901 = Temporal.PlainDate.from({ year: 2019, monthCode: "M01", day: 1, calendar }, options);
@@ -138,17 +146,22 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date200012.subtract(months6),
+  2001, 6, "M05", 1, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDate(
+  date200012.subtract(months6n),
   2000, 6, "M06", 1, "Subtracting 6 months, with result in same year"
 );
 
 for (var duration of durations) {
   for (var start of dates) {
-    const end = start.subtract(duration.negated());
+    const end = start.subtract(duration);
 
     // startYesterday = start - (1 day)
     const startYesterday = start.subtract({ days: 1 });
     // endYesterday = startYesterday + duration
-    const endYesterday = startYesterday.subtract(duration.negated());
+    const endYesterday = startYesterday.subtract(duration);
     // When adding months, the result day should be the same
     // unless there are fewer days in the destination month than the source day
     assert.sameValue(endYesterday.day, Math.min(startYesterday.day, endYesterday.daysInMonth), "adding months should result in same day");
@@ -182,7 +195,8 @@ for (var duration of durations) {
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 1, calendar }, options);
 const date20000101 = Temporal.PlainDate.from({ year: 2000, month: 1, day: 1, calendar }, options);
@@ -209,6 +223,11 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date20000101.subtract(weeks40),
+  2000, 10, "M10", 16, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDate(
+  date20000101.subtract(weeks40n),
   1999, 3, "M03", 16, "subtract 40 weeks, ending in previous year"
 );
 
@@ -216,7 +235,8 @@ TemporalHelpers.assertPlainDate(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.PlainDate.from({ year: 2021, monthCode: "M01", day: 29, calendar }, options);
 
@@ -252,5 +272,10 @@ TemporalHelpers.assertPlainDate(
 
 TemporalHelpers.assertPlainDate(
   date20000101.subtract(days200),
+  2000, 7, "M07", 24, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDate(
+  date20000101.subtract(days200n),
   1999, 6, "M06", 8, "subtract 200 days, ending in previous year"
 );
diff --git a/test/intl402/Temporal/PlainDateTime/prototype/add/basic-chinese.js b/test/intl402/Temporal/PlainDateTime/prototype/add/basic-chinese.js
index b44446ee02..93f43edba7 100644
--- a/test/intl402/Temporal/PlainDateTime/prototype/add/basic-chinese.js
+++ b/test/intl402/Temporal/PlainDateTime/prototype/add/basic-chinese.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.PlainDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, calendar }, options);
 const date202302 = Temporal.PlainDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date199712.add(years3months6days17n),
+  1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,6 +81,7 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 
 const date201901 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date201906 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, calendar }, options);
@@ -127,11 +134,17 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date200012.add(months6n),
+  2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
+);
+
 // Weeks
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date20000101 = Temporal.PlainDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, calendar }, options);
@@ -161,11 +174,17 @@ TemporalHelpers.assertPlainDateTime(
   2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(weeks40n),
+  1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, calendar }, options);
 
@@ -203,3 +222,8 @@ TemporalHelpers.assertPlainDateTime(
   date20000101.add(days200),
   2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(days200n),
+  1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/PlainDateTime/prototype/add/basic-dangi.js b/test/intl402/Temporal/PlainDateTime/prototype/add/basic-dangi.js
index bde8805d0a..e933b360f2 100644
--- a/test/intl402/Temporal/PlainDateTime/prototype/add/basic-dangi.js
+++ b/test/intl402/Temporal/PlainDateTime/prototype/add/basic-dangi.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.PlainDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, calendar }, options);
 const date202302 = Temporal.PlainDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date199712.add(years3months6days17n),
+  1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,6 +81,7 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 
 const date201901 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date201906 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, calendar }, options);
@@ -127,11 +134,17 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date200012.add(months6n),
+  2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
+);
+
 // Weeks
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date20000101 = Temporal.PlainDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, calendar }, options);
@@ -161,11 +174,17 @@ TemporalHelpers.assertPlainDateTime(
   2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(weeks40n),
+  1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, calendar }, options);
 
@@ -203,3 +222,8 @@ TemporalHelpers.assertPlainDateTime(
   date20000101.add(days200),
   2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(days200n),
+  1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-chinese.js b/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-chinese.js
index 6cd5fca186..1a2c7b65c4 100644
--- a/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-chinese.js
+++ b/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-chinese.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.PlainDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, calendar }, options);
 const date202302 = Temporal.PlainDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date199712.subtract(years3months6days17),
+  2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date199712.subtract(years3months6days17n),
   1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,7 +80,8 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 
 const date201901 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date201906 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, calendar }, options);
@@ -124,6 +131,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date200012.subtract(months6),
+  2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date200012.subtract(months6n),
   2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
 );
 
@@ -131,7 +143,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date20000101 = Temporal.PlainDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, calendar }, options);
@@ -158,6 +171,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(weeks40),
+  2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(weeks40n),
   1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
 );
 
@@ -165,7 +183,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, calendar }, options);
 
@@ -201,5 +220,10 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(days200),
+  2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(days200n),
   1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
 );
diff --git a/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-dangi.js b/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-dangi.js
index 6ff353fc21..a09fcfe3bf 100644
--- a/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-dangi.js
+++ b/test/intl402/Temporal/PlainDateTime/prototype/subtract/basic-dangi.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.PlainDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, calendar }, options);
 const date202302 = Temporal.PlainDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date199712.subtract(years3months6days17),
+  2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date199712.subtract(years3months6days17n),
   1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,7 +80,8 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 
 const date201901 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date201906 = Temporal.PlainDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, calendar }, options);
@@ -124,6 +131,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date200012.subtract(months6),
+  2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date200012.subtract(months6n),
   2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
 );
 
@@ -131,7 +143,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, calendar }, options);
 const date20000101 = Temporal.PlainDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, calendar }, options);
@@ -158,6 +171,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(weeks40),
+  2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(weeks40n),
   1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
 );
 
@@ -165,7 +183,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.PlainDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, calendar }, options);
 
@@ -201,5 +220,10 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(days200),
+  2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(days200n),
   1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
 );
diff --git a/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-chinese.js b/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-chinese.js
index 6a530fc5d4..32cf47abcc 100644
--- a/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-chinese.js
+++ b/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-chinese.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.ZonedDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date202302 = Temporal.ZonedDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date199712.add(years3months6days17n).toPlainDateTime(),
+  1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,6 +81,7 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 
 const date201901 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date201906 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -127,11 +134,17 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date200012.add(months6n).toPlainDateTime(),
+  2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
+);
+
 // Weeks
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date20000101 = Temporal.ZonedDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -161,11 +174,17 @@ TemporalHelpers.assertPlainDateTime(
   2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(weeks40n).toPlainDateTime(),
+  1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 
@@ -203,3 +222,8 @@ TemporalHelpers.assertPlainDateTime(
   date20000101.add(days200).toPlainDateTime(),
   2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(days200n).toPlainDateTime(),
+  1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-dangi.js b/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-dangi.js
index 2cfa75b891..7fc8b6a539 100644
--- a/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-dangi.js
+++ b/test/intl402/Temporal/ZonedDateTime/prototype/add/basic-dangi.js
@@ -18,6 +18,7 @@ const years1n = new Temporal.Duration(-1);
 const years5 = new Temporal.Duration(5);
 const years5n = new Temporal.Duration(-5);
 const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17n = new Temporal.Duration(-3, -6, 0, -17);
 
 const date201802 = Temporal.ZonedDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date202302 = Temporal.ZonedDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -68,6 +69,11 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date199712.add(years3months6days17n).toPlainDateTime(),
+  1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
+);
+
 // Months
 
 const months1 = new Temporal.Duration(0, 1);
@@ -75,6 +81,7 @@ const months1n = new Temporal.Duration(0, -1);
 const months4 = new Temporal.Duration(0, 4);
 const months4n = new Temporal.Duration(0, -4);
 const months6 = new Temporal.Duration(0, 6);
+const months6n = new Temporal.Duration(0, -6);
 
 const date201901 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date201906 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -127,11 +134,17 @@ TemporalHelpers.assertPlainDateTime(
   2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date200012.add(months6n).toPlainDateTime(),
+  2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
+);
+
 // Weeks
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ 2, /* weeks = */ 3);
 const months2weeks3n = new Temporal.Duration(0, -2, -3);
 const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40n = new Temporal.Duration(0, 0, -40);
 
 const date202101 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date20000101 = Temporal.ZonedDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -161,11 +174,17 @@ TemporalHelpers.assertPlainDateTime(
   2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
 );
 
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(weeks40n).toPlainDateTime(),
+  1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
+);
+
 // Days
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ 10);
 const days10n = new Temporal.Duration(0, 0, 0, -10);
 const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200n = new Temporal.Duration(0, 0, 0, -200);
 
 const date20210129 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 
@@ -203,3 +222,8 @@ TemporalHelpers.assertPlainDateTime(
   date20000101.add(days200).toPlainDateTime(),
   2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
 );
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.add(days200n).toPlainDateTime(),
+  1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
+);
diff --git a/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-chinese.js b/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-chinese.js
index 0fe30a2880..d80a752407 100644
--- a/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-chinese.js
+++ b/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-chinese.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.ZonedDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date202302 = Temporal.ZonedDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date199712.subtract(years3months6days17).toPlainDateTime(),
+  2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date199712.subtract(years3months6days17n).toPlainDateTime(),
   1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,7 +80,8 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 
 const date201901 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date201906 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -124,6 +131,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date200012.subtract(months6).toPlainDateTime(),
+  2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date200012.subtract(months6n).toPlainDateTime(),
   2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
 );
 
@@ -131,7 +143,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date20000101 = Temporal.ZonedDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -158,6 +171,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(weeks40).toPlainDateTime(),
+  2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(weeks40n).toPlainDateTime(),
   1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
 );
 
@@ -165,7 +183,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 
@@ -201,5 +220,10 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(days200).toPlainDateTime(),
+  2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(days200n).toPlainDateTime(),
   1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
 );
diff --git a/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-dangi.js b/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-dangi.js
index 6fa874e91c..68c31c159e 100644
--- a/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-dangi.js
+++ b/test/intl402/Temporal/ZonedDateTime/prototype/subtract/basic-dangi.js
@@ -17,7 +17,8 @@ const years1 = new Temporal.Duration(-1);
 const years1n = new Temporal.Duration(1);
 const years5 = new Temporal.Duration(-5);
 const years5n = new Temporal.Duration(5);
-const years3months6days17 = new Temporal.Duration(3, 6, 0, 17);
+const years3months6days17 = new Temporal.Duration(-3, -6, 0, -17);
+const years3months6days17n = new Temporal.Duration(3, 6, 0, 17);
 
 const date201802 = Temporal.ZonedDateTime.from({ year: 2018, monthCode: "M02", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date202302 = Temporal.ZonedDateTime.from({ year: 2023, monthCode: "M02", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -65,6 +66,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date199712.subtract(years3months6days17).toPlainDateTime(),
+  2001, 6, "M05", 18, 12, 34, 0, 0, 0, 0, "Adding 3 years/6 months/17 days to day 1 of a month"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date199712.subtract(years3months6days17n).toPlainDateTime(),
   1994, 5, "M05", 14, 12, 34, 0, 0, 0, 0, "Subtracting 3 years/6 months/17 days from day 1 of a month"
 );
 
@@ -74,7 +80,8 @@ const months1 = new Temporal.Duration(0, -1);
 const months1n = new Temporal.Duration(0, 1);
 const months4 = new Temporal.Duration(0, -4);
 const months4n = new Temporal.Duration(0, 4);
-const months6 = new Temporal.Duration(0, 6);
+const months6 = new Temporal.Duration(0, -6);
+const months6n = new Temporal.Duration(0, 6);
 
 const date201901 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date201906 = Temporal.ZonedDateTime.from({ year: 2019, monthCode: "M06", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -124,6 +131,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date200012.subtract(months6).toPlainDateTime(),
+  2001, 6, "M05", 1, 12, 34, 0, 0, 0, 0, "Adding 6 months, with result in next year (leap year)"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date200012.subtract(months6n).toPlainDateTime(),
   2000, 6, "M06", 1, 12, 34, 0, 0, 0, 0, "Subtracting 6 months, with result in same year"
 );
 
@@ -131,7 +143,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const months2weeks3 = new Temporal.Duration(0, /* months = */ -2, /* weeks = */ -3);
 const months2weeks3n = new Temporal.Duration(0, 2, 3);
-const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ 40);
+const weeks40 = new Temporal.Duration(0, 0, /* weeks = */ -40);
+const weeks40n = new Temporal.Duration(0, 0, 40);
 
 const date202101 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 const date20000101 = Temporal.ZonedDateTime.from({ year: 2000, month: 1, day: 1, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
@@ -158,6 +171,11 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(weeks40).toPlainDateTime(),
+  2000, 10, "M10", 16, 12, 34, 0, 0, 0, 0, "add 40 weeks, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(weeks40n).toPlainDateTime(),
   1999, 3, "M03", 16, 12, 34, 0, 0, 0, 0, "subtract 40 weeks, ending in previous year"
 );
 
@@ -165,7 +183,8 @@ TemporalHelpers.assertPlainDateTime(
 
 const days10 = new Temporal.Duration(0, 0, 0, /* days = */ -10);
 const days10n = new Temporal.Duration(0, 0, 0, 10);
-const days200 = new Temporal.Duration(0, 0, 0, /* days = */ 200);
+const days200 = new Temporal.Duration(0, 0, 0, /* days = */ -200);
+const days200n = new Temporal.Duration(0, 0, 0, 200);
 
 const date20210129 = Temporal.ZonedDateTime.from({ year: 2021, monthCode: "M01", day: 29, hour: 12, minute: 34, timeZone: "UTC", calendar }, options);
 
@@ -201,5 +220,10 @@ TemporalHelpers.assertPlainDateTime(
 
 TemporalHelpers.assertPlainDateTime(
   date20000101.subtract(days200).toPlainDateTime(),
+  2000, 7, "M07", 24, 12, 34, 0, 0, 0, 0, "add 200 days, ending in same year"
+);
+
+TemporalHelpers.assertPlainDateTime(
+  date20000101.subtract(days200n).toPlainDateTime(),
   1999, 6, "M06", 8, 12, 34, 0, 0, 0, 0, "subtract 200 days, ending in previous year"
 );