1 files changed, 33 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/resist-fingerprinting/timezone.js b/js/src/jit-test/tests/resist-fingerprinting/timezone.js
new file mode 100644
index 0000000000..64e6f86eee
--- /dev/null
+++ b/js/src/jit-test/tests/resist-fingerprinting/timezone.js
@@ -0,0 +1,33 @@
+// |jit-test| tz-pacific; skip-if: typeof Intl === 'undefined'
+
+let tzRE = /\(([^\)]+)\)/;
+
+// Make sure we aren't already running with UTC
+let original = new Date(0);
+assertEq(tzRE.exec(original.toString())[1], "Pacific Standard Time");
+
+let originalDT = Intl.DateTimeFormat("en-US", {
+  dateStyle: "full",
+  timeStyle: "full",
+});
+assertEq(originalDT.format(original).endsWith("Pacific Standard Time"), true);
+assertEq(originalDT.resolvedOptions().timeZone, "PST8PDT");
+
+let global = newGlobal({shouldResistFingerprinting: true});
+
+let date = new global.Date();
+assertEq(tzRE.exec(date.toString())[1], "Coordinated Universal Time");
+assertEq(tzRE.exec(date.toTimeString())[1], "Coordinated Universal Time");
+assertEq(date.getFullYear(), date.getUTCFullYear());
+assertEq(date.getMonth(), date.getUTCMonth());
+assertEq(date.getDate(), date.getUTCDate());
+assertEq(date.getDay(), date.getUTCDay());
+assertEq(date.getHours(),date.getUTCHours());
+assertEq(date.getTimezoneOffset(), 0);
+
+let dt = global.Intl.DateTimeFormat("en-US", {
+  dateStyle: "full",
+  timeStyle: "full",
+});
+assertEq(dt.format(date).endsWith("Coordinated Universal Time"), true);
+assertEq(dt.resolvedOptions().timeZone, "UTC");