diff --git a/test/intl402/DateTimeFormat/prototype/format/numbering-system.js b/test/intl402/DateTimeFormat/prototype/format/numbering-system.js
new file mode 100644
index 0000000000..fa0825a8c4
--- /dev/null
+++ b/test/intl402/DateTimeFormat/prototype/format/numbering-system.js
@@ -0,0 +1,59 @@
+// Copyright 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-formatdatetimepattern
+description: |
+  Checks that numberingSystem property used correctly.
+info: >
+  11.5.5 FormatDateTimePattern ( dateTimeFormat, format, pattern, epochNanoseconds )
+    ...
+    3. Perform ! CreateDataPropertyOrThrow(nfOptions, "numberingSystem", dateTimeFormat.[[NumberingSystem]]).
+    ...
+    8. Perform ! CreateDataPropertyOrThrow(nf2Options, "numberingSystem", dateTimeFormat.[[NumberingSystem]]).
+    ...
+    11. If format has a field [[fractionalSecondDigits]], then
+    ...
+      d. Perform ! CreateDataPropertyOrThrow(nf3Options, "numberingSystem", dateTimeFormat.[[NumberingSystem]]).
+
+locale: [en-US, en-US-u-nu-arab, en-US-u-nu-deva, en-US-u-nu-hanidec]
+---*/
+
+const localesAndResults = [
+  [ "en-US", "2:35:06", "2:35:06.789", "02:35:06", "6" ],
+  [ "en-US-u-nu-arab", "٢:٣٥:٠٦", "٢:٣٥:٠٦٫٧٨٩", "٠٢:٣٥:٠٦", "٦" ],
+  [ "en-US-u-nu-deva", "२:३५:०६", "२:३५:०६.७८९", "०२:३५:०६", "६" ],
+  [ "en-US-u-nu-hanidec", "二:三五:〇六", "二:三五:〇六.七八九", "〇二:三五:〇六 AM", "六" ],
+]
+const time = new Date(2024, 0, 1, 2, 35, 6, 789);
+
+for (const [locale, expectedNoFractional, expectedFractional, expectedTwoDigit, expectedAllNumeric] of localesAndResults) {
+  const formattedNoFractional = new Intl.DateTimeFormat(locale, {
+      hour: "numeric",
+      minute: "numeric",
+      second: "numeric",
+    }).format(time);
+
+  const formattedFractional = new Intl.DateTimeFormat(locale, {
+      hour: "numeric",
+      minute: "numeric",
+      second: "numeric",
+      fractionalSecondDigits: 3,
+    }).format(time);
+
+  const formattedTwoDigit = new Intl.DateTimeFormat(locale, {
+      hour: "2-digit",
+      minute: "2-digit",
+      second: "2-digit",
+    }).format(time);
+
+  const formattedAllNumeric = new Intl.DateTimeFormat(locale, {
+      second: "numeric",
+    }).format(time);
+
+  assert.sameValue(formattedNoFractional.includes(expectedNoFractional), true, `${locale}: display without fractionalSecondDigits`);
+  assert.sameValue(formattedFractional.includes(expectedFractional), true, `${locale}: display with fractionalSecondDigits`);
+  assert.sameValue(formattedTwoDigit.includes(expectedTwoDigit), true, `${locale}: display all time units in 2-digit`);
+  assert.sameValue(formattedAllNumeric.includes(expectedAllNumeric), true,`${locale}: display one numeric-styled unit`);
+}
+
diff --git a/test/intl402/RelativeTimeFormat/prototype/format/en-us-numbering-systems.js b/test/intl402/RelativeTimeFormat/prototype/format/en-us-numbering-systems.js
new file mode 100644
index 0000000000..84a5423d8c
--- /dev/null
+++ b/test/intl402/RelativeTimeFormat/prototype/format/en-us-numbering-systems.js
@@ -0,0 +1,27 @@
+// Copyright 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.RelativeTimeFormat.prototype.format
+description: Checks that numberingSystem option used correctly.
+info: |
+    17.5.2 PartitionRelativeTimePattern ( relativeTimeFormat, value, unit )
+
+    11. Let fv be PartitionNumberPattern(relativeTimeFormat.[[NumberFormat]], ℝ(value)).
+
+locale: [en-US]
+---*/
+
+const localesAndResults = [
+  ["en-US"],
+  ["en-US-u-nu-arab"],
+  ["en-US-u-nu-deva"],
+  ["en-US-u-nu-hanidec"],
+];
+const seconds = 1234567890;
+
+for (const locale of localesAndResults){
+  const formatted = new Intl.RelativeTimeFormat(locale, {style: "short"}).format(seconds, "seconds");
+  const expected = new Intl.NumberFormat(locale).format(seconds);
+  assert.sameValue(formatted.includes(expected), true, `locale: ${locale}`);
+}