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diff --git a/js/src/tests/test262/built-ins/Temporal/ZonedDateTime/prototype/millisecond/balance-negative-time-units.js b/js/src/tests/test262/built-ins/Temporal/ZonedDateTime/prototype/millisecond/balance-negative-time-units.js
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+++ b/js/src/tests/test262/built-ins/Temporal/ZonedDateTime/prototype/millisecond/balance-negative-time-units.js
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+// |reftest| skip-if(!this.hasOwnProperty('Temporal')) -- Temporal is not enabled unconditionally
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.millisecond
+description: Negative time fields are balanced upwards
+info: |
+    sec-temporal-balancetime steps 3–6:
+      3. Set _microsecond_ to _microsecond_ + floor(_nanosecond_ / 1000).
+      4. Set _nanosecond_ to _nanosecond_ modulo 1000.
+      5. Set _millisecond_ to _millisecond_ + floor(_microsecond_ / 1000).
+      6. Set _microsecond_ to _microsecond_ modulo 1000.
+    sec-temporal-balanceisodatetime step 1:
+      1. Let _balancedTime_ be ? BalanceTime(_hour_, _minute_, _second_, _millisecond_, _microsecond_, _nanosecond_).
+    sec-temporal-builtintimezonegetplaindatetimefor step 3:
+      3. Set _result_ to ? BalanceISODateTime(_result_.[[Year]], _result_.[[Month]], _result_.[[Day]], _result_.[[Hour]], _result_.[[Minute]], _result_.[[Second]], _result_.[[Millisecond]], _result_.[[Microsecond]], _result_.[[Nanosecond]] + _offsetNanoseconds_).
+    sec-get-temporal.zoneddatetime.prototype.millisecond step 6:
+      6. Let _temporalDateTime_ be ? BuiltinTimeZoneGetPlainDateTimeFor(_timeZone_, _instant_, _calendar_).
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+// This code path is encountered if the time zone offset is negative and its
+// absolute value in nanoseconds is greater than the nanosecond field of the
+// exact time's epoch parts
+const tz = TemporalHelpers.specificOffsetTimeZone(-2);
+const datetime = new Temporal.ZonedDateTime(1_000_001n, tz);
+
+assert.sameValue(datetime.millisecond, 0);
+assert.sameValue(datetime.microsecond, 999);
+assert.sameValue(datetime.nanosecond, 999);
+
+reportCompare(0, 0);