diff --git a/packages/core/src/utils/dateToLocaleISOString.newfoundland.spec.js b/packages/core/src/utils/dateToLocaleISOString.newfoundland.spec.js
new file mode 100644
index 0000000000..a2f1132c7a
--- /dev/null
+++ b/packages/core/src/utils/dateToLocaleISOString.newfoundland.spec.js
@@ -0,0 +1,14 @@
+/**
+ * @jest-environment ../../../__tests__/setup/jestNodeEnvironmentWithTimezone.js
+ * @timezone America/St_Johns
+ */
+
+import dateToLocaleISOString from './dateToLocaleISOString';
+
+test('formatting a time in Cananda, Newfoundland timezone', () => {
+  // eslint-disable-next-line no-magic-numbers
+  const date = new Date(Date.UTC(2000, 0, 1, 0, 12, 34, 567));
+  const actual = dateToLocaleISOString(date);
+
+  expect(actual).toMatchInlineSnapshot(`"2000-01-01T09:12:34.567-03:30"`);
+});