diff --git a/test/intl402/Temporal/Instant/prototype/toLocaleString/default-includes-time-not-time-zone-name.js b/test/intl402/Temporal/Instant/prototype/toLocaleString/default-includes-time-not-time-zone-name.js
new file mode 100644
index 0000000000..5b7b78f1dd
--- /dev/null
+++ b/test/intl402/Temporal/Instant/prototype/toLocaleString/default-includes-time-not-time-zone-name.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.instant.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en]
+features: [Temporal]
+---*/
+
+const instant = new Temporal.Instant(1735213600_321_000_000n); // 2024-12-26T11:46:40.321Z
+const result = instant.toLocaleString("en", { timeZone: "UTC" });
+
+assert(result.includes("2024"), `Instant formatted with no options ${result} should include year`);
+assert(result.includes("12") || result.includes("Dec"), `Instant formatted with no options ${result} should include month`);
+assert(result.includes("26"), `Instant formatted with no options ${result} should include day`);
+assert(result.includes("11"), `Instant formatted with no options ${result} should include hour`);
+assert(result.includes("46"), `Instant formatted with no options ${result} should include minute`);
+assert(result.includes("40"), `Instant formatted with no options ${result} should include second`);
+assert(!result.includes("321"), `Instant formatted with no options ${result} should not include fractional second digits`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `Instant formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/PlainDate/prototype/toLocaleString/default-does-not-include-time-and-time-zone-name.js b/test/intl402/Temporal/PlainDate/prototype/toLocaleString/default-does-not-include-time-and-time-zone-name.js
new file mode 100644
index 0000000000..8fa20057fa
--- /dev/null
+++ b/test/intl402/Temporal/PlainDate/prototype/toLocaleString/default-does-not-include-time-and-time-zone-name.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en]
+features: [Temporal]
+---*/
+
+const plainDate = new Temporal.PlainDate(2024, 12, 26);
+const result = plainDate.toLocaleString("en", { timeZone: "UTC" });
+
+assert(result.includes("2024"), `PlainDate formatted with no options ${result} should include year`);
+assert(result.includes("12") || result.includes("Dec"), `PlainDate formatted with no options ${result} should include month`);
+assert(result.includes("26"), `PlainDate formatted with no options ${result} should include day`);
+assert(!result.includes("00"), `PlainDate formatted with no options ${result} should not include hour, minute, second`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `PlainDate formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/PlainDateTime/prototype/toLocaleString/default-includes-time-not-time-zone-name.js b/test/intl402/Temporal/PlainDateTime/prototype/toLocaleString/default-includes-time-not-time-zone-name.js
new file mode 100644
index 0000000000..654fc01727
--- /dev/null
+++ b/test/intl402/Temporal/PlainDateTime/prototype/toLocaleString/default-includes-time-not-time-zone-name.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en]
+features: [Temporal]
+---*/
+
+const plainDateTime = new Temporal.PlainDateTime(2024, 12, 26, 11, 46, 40, 321);
+const result = plainDateTime.toLocaleString("en", { timeZone: "UTC" });
+
+assert(result.includes("2024"), `PlainDateTime formatted with no options ${result} should include year`);
+assert(result.includes("12") || result.includes("Dec"), `PlainDateTime formatted with no options ${result} should include month`);
+assert(result.includes("26"), `PlainDateTime formatted with no options ${result} should include day`);
+assert(result.includes("11"), `PlainDateTime formatted with no options ${result} should include hour`);
+assert(result.includes("46"), `PlainDateTime formatted with no options ${result} should include minute`);
+assert(result.includes("40"), `PlainDateTime formatted with no options ${result} should include second`);
+assert(!result.includes("321"), `PlainDateTime formatted with no options ${result} should not include fractional second digits`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `PlainDateTime formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/PlainMonthDay/prototype/toLocaleString/default-does-not-include-year-time-and-time-zone-name.js b/test/intl402/Temporal/PlainMonthDay/prototype/toLocaleString/default-does-not-include-year-time-and-time-zone-name.js
new file mode 100644
index 0000000000..06ba488394
--- /dev/null
+++ b/test/intl402/Temporal/PlainMonthDay/prototype/toLocaleString/default-does-not-include-year-time-and-time-zone-name.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainmonthday.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en-u-ca-iso8601]
+features: [Temporal]
+---*/
+
+const plainMonthDay = new Temporal.PlainMonthDay(12, 26);
+const result = plainMonthDay.toLocaleString("en-u-ca-iso8601", { timeZone: "UTC" });
+
+assert(!result.includes("1972"), `PlainMonthDay formatted with no options ${result} should not include reference year`);
+assert(result.includes("12") || result.includes("Dec"), `PlainMonthDay formatted with no options ${result} should include month`);
+assert(result.includes("26"), `PlainMonthDay formatted with no options ${result} should include day`);
+assert(!result.includes("00"), `PlainMonthDay formatted with no options ${result} should not include hour, minute, second`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `PlainMonthDay formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/PlainTime/prototype/toLocaleString/default-does-not-include-date-and-time-zone-name.js b/test/intl402/Temporal/PlainTime/prototype/toLocaleString/default-does-not-include-date-and-time-zone-name.js
new file mode 100644
index 0000000000..b9b95bb961
--- /dev/null
+++ b/test/intl402/Temporal/PlainTime/prototype/toLocaleString/default-does-not-include-date-and-time-zone-name.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en]
+features: [Temporal]
+---*/
+
+const plainTime = new Temporal.PlainTime(11, 46, 40, 321);
+const result = plainTime.toLocaleString("en", { timeZone: "UTC" });
+
+assert(!result.includes("1970"), `PlainTime formatted with no options ${result} should not include year`);
+assert(!result.includes("01") && !result.includes("Jan"), `PlainTime formatted with no options ${result} should not include month or day`);
+assert(result.includes("11"), `PlainTime formatted with no options ${result} should include hour`);
+assert(result.includes("46"), `PlainTime formatted with no options ${result} should include minute`);
+assert(result.includes("40"), `PlainTime formatted with no options ${result} should include second`);
+assert(!result.includes("321"), `PlainTime formatted with no options ${result} should not include fractional second digits`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `PlainTime formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/PlainYearMonth/prototype/toLocaleString/default-does-not-include-day-time-and-time-zone-name.js b/test/intl402/Temporal/PlainYearMonth/prototype/toLocaleString/default-does-not-include-day-time-and-time-zone-name.js
new file mode 100644
index 0000000000..4401aecbac
--- /dev/null
+++ b/test/intl402/Temporal/PlainYearMonth/prototype/toLocaleString/default-does-not-include-day-time-and-time-zone-name.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plainyearmonth.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en-u-ca-iso8601]
+features: [Temporal]
+---*/
+
+const plainYearMonth = new Temporal.PlainYearMonth(2024, 12, "iso8601", 26);  // nonstandard reference day
+const result = plainYearMonth.toLocaleString("en-u-ca-iso8601", { timeZone: "UTC" });
+
+assert(result.includes("2024"), `PlainYearMonth formatted with no options ${result} should include year`);
+assert(result.includes("12") || result.includes("Dec"), `PlainYearMonth formatted with no options ${result} should include month`);
+assert(!result.includes("26"), `PlainYearMonth formatted with no options ${result} should not include reference day`);
+assert(!result.includes("00"), `PlainYearMonth formatted with no options ${result} should not include hour, minute, second`);
+assert(
+  !result.includes("UTC") && !result.includes("Coordinated Universal Time"),
+  `PlainYearMonth formatted with no options ${result} should not include time zone name`
+);
diff --git a/test/intl402/Temporal/ZonedDateTime/prototype/toLocaleString/default-includes-time-and-time-zone-name.js b/test/intl402/Temporal/ZonedDateTime/prototype/toLocaleString/default-includes-time-and-time-zone-name.js
new file mode 100644
index 0000000000..b4275f62ee
--- /dev/null
+++ b/test/intl402/Temporal/ZonedDateTime/prototype/toLocaleString/default-includes-time-and-time-zone-name.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.tolocalestring
+description: Tests what information is present by default
+locale: [en]
+features: [Temporal]
+---*/
+
+const zonedDateTime = new Temporal.ZonedDateTime(1735213600_321_000_000n, "UTC"); // 2024-12-26T11:46:40.321Z
+const result = zonedDateTime.toLocaleString("en");
+
+assert(result.includes("2024"), `ZonedDateTime formatted with no options ${result} should include year`);
+assert(result.includes("12") || result.includes("Dec"), `ZonedDateTime formatted with no options ${result} should include month`);
+assert(result.includes("26"), `ZonedDateTime formatted with no options ${result} should include day`);
+assert(result.includes("11"), `ZonedDateTime formatted with no options ${result} should include hour`);
+assert(result.includes("46"), `ZonedDateTime formatted with no options ${result} should include minute`);
+assert(result.includes("40"), `ZonedDateTime formatted with no options ${result} should include second`);
+assert(!result.includes("321"), `ZonedDateTime formatted with no options ${result} should not include fractional second digits`);
+assert(
+  result.includes("UTC") || result.includes("Coordinated Universal Time"),
+  `ZonedDateTime formatted with no options ${result} should include time zone name`
+);