diff --git a/polyfill/lib/plaindate.mjs b/polyfill/lib/plaindate.mjs
index 62ecdd3849..69f2449d3e 100644
--- a/polyfill/lib/plaindate.mjs
+++ b/polyfill/lib/plaindate.mjs
@@ -329,17 +329,26 @@ export class PlainDate {
     const calendar = ES.ConsolidateCalendars(dateCalendar, timeCalendar);
     return new DateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond, calendar);
   }
-  toZonedDateTime(timeZoneLike, temporalTime = undefined, options = undefined) {
+  toZonedDateTime(item) {
     if (!ES.IsTemporalDate(this)) throw new TypeError('invalid receiver');
-    const timeZone = ES.ToTemporalTimeZone(timeZoneLike);
-    options = ES.NormalizeOptionsObject(options);
-    const disambiguation = ES.ToTemporalDisambiguation(options);
+
+    let timeZone, temporalTime;
+    if (ES.Type(item) === 'Object') {
+      let timeZoneLike = item.timeZone;
+      if (timeZoneLike === undefined) {
+        timeZone = ES.ToTemporalTimeZone(item);
+      } else {
+        timeZone = ES.ToTemporalTimeZone(timeZoneLike);
+        temporalTime = item.time;
+      }
+    } else {
+      timeZone = ES.ToTemporalTimeZone(item);
+    }
 
     const year = GetSlot(this, ISO_YEAR);
     const month = GetSlot(this, ISO_MONTH);
     const day = GetSlot(this, ISO_DAY);
     const calendar = GetSlot(this, CALENDAR);
-    const DateTime = GetIntrinsic('%Temporal.PlainDateTime%');
 
     let hour = 0,
       minute = 0,
@@ -357,8 +366,20 @@ export class PlainDate {
       nanosecond = GetSlot(temporalTime, ISO_NANOSECOND);
     }
 
-    const dt = new DateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond, calendar);
-    const instant = ES.GetTemporalInstantFor(timeZone, dt, disambiguation);
+    const PlainDateTime = GetIntrinsic('%Temporal.PlainDateTime%');
+    const dt = new PlainDateTime(
+      year,
+      month,
+      day,
+      hour,
+      minute,
+      second,
+      millisecond,
+      microsecond,
+      nanosecond,
+      calendar
+    );
+    const instant = ES.GetTemporalInstantFor(timeZone, dt, 'compatible');
     const ZonedDateTime = GetIntrinsic('%Temporal.ZonedDateTime%');
     return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZone, calendar);
   }
diff --git a/polyfill/lib/plaintime.mjs b/polyfill/lib/plaintime.mjs
index 503c6adcaf..a77f46480e 100644
--- a/polyfill/lib/plaintime.mjs
+++ b/polyfill/lib/plaintime.mjs
@@ -399,12 +399,24 @@ export class PlainTime {
     const DateTime = GetIntrinsic('%Temporal.PlainDateTime%');
     return new DateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond, calendar);
   }
-  toZonedDateTime(timeZoneLike, temporalDate, options = undefined) {
+  toZonedDateTime(item) {
     if (!ES.IsTemporalTime(this)) throw new TypeError('invalid receiver');
+
+    if (ES.Type(item) !== 'Object') {
+      throw new TypeError('invalid argument');
+    }
+
+    const dateLike = item.date;
+    if (dateLike === undefined) {
+      throw new TypeError('missing date property');
+    }
+    const temporalDate = ES.ToTemporalDate(dateLike, GetIntrinsic('%Temporal.PlainDate%'));
+
+    const timeZoneLike = item.timeZone;
+    if (timeZoneLike === undefined) {
+      throw new TypeError('missing timeZone property');
+    }
     const timeZone = ES.ToTemporalTimeZone(timeZoneLike);
-    temporalDate = ES.ToTemporalDate(temporalDate, GetIntrinsic('%Temporal.PlainDate%'));
-    options = ES.NormalizeOptionsObject(options);
-    const disambiguation = ES.ToTemporalDisambiguation(options);
 
     const year = GetSlot(temporalDate, ISO_YEAR);
     const month = GetSlot(temporalDate, ISO_MONTH);
@@ -416,10 +428,21 @@ export class PlainTime {
     const millisecond = GetSlot(this, ISO_MILLISECOND);
     const microsecond = GetSlot(this, ISO_MICROSECOND);
     const nanosecond = GetSlot(this, ISO_NANOSECOND);
-    const DateTime = GetIntrinsic('%Temporal.PlainDateTime%');
 
-    const dt = new DateTime(year, month, day, hour, minute, second, millisecond, microsecond, nanosecond, calendar);
-    const instant = ES.GetTemporalInstantFor(timeZone, dt, disambiguation);
+    const PlainDateTime = GetIntrinsic('%Temporal.PlainDateTime%');
+    const dt = new PlainDateTime(
+      year,
+      month,
+      day,
+      hour,
+      minute,
+      second,
+      millisecond,
+      microsecond,
+      nanosecond,
+      calendar
+    );
+    const instant = ES.GetTemporalInstantFor(timeZone, dt, 'compatible');
     const ZonedDateTime = GetIntrinsic('%Temporal.ZonedDateTime%');
     return new ZonedDateTime(GetSlot(instant, EPOCHNANOSECONDS), timeZone, calendar);
   }
diff --git a/polyfill/test/plaindate.mjs b/polyfill/test/plaindate.mjs
index bbcfb75901..b45a1c4e5c 100644
--- a/polyfill/test/plaindate.mjs
+++ b/polyfill/test/plaindate.mjs
@@ -208,49 +208,33 @@ describe('Date', () => {
       const date = PlainDate.from('2020-01-01');
       const time = Temporal.PlainTime.from('12:00');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      equal(`${date.toZonedDateTime(tz, time)}`, '2020-01-01T12:00:00-08:00[America/Los_Angeles]');
+      const zdt = date.toZonedDateTime({ timeZone: tz, time });
+      equal(`${zdt}`, '2020-01-01T12:00:00-08:00[America/Los_Angeles]');
     });
-    it('works with time omitted', () => {
+    it('works with time omitted (timeZone argument)', () => {
       const date = PlainDate.from('2020-01-01');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      equal(`${date.toZonedDateTime(tz)}`, '2020-01-01T00:00:00-08:00[America/Los_Angeles]');
+      const zdt = date.toZonedDateTime(tz);
+      equal(`${zdt}`, '2020-01-01T00:00:00-08:00[America/Los_Angeles]');
     });
-    it('works with disambiguation option', () => {
-      const date = PlainDate.from('2020-03-08');
-      const time = Temporal.PlainTime.from('02:00');
+    it('works with time omitted (timeZone property)', () => {
+      const date = PlainDate.from('2020-01-01');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      const zdt = date.toZonedDateTime(tz, time, { disambiguation: 'earlier' });
-      equal(`${zdt}`, '2020-03-08T01:00:00-08:00[America/Los_Angeles]');
+      const zdt = date.toZonedDateTime({ timeZone: tz });
+      equal(`${zdt}`, '2020-01-01T00:00:00-08:00[America/Los_Angeles]');
     });
-    it('casts first argument', () => {
+    it('casts timeZone property', () => {
       const date = PlainDate.from('2020-07-08');
       const time = Temporal.PlainTime.from('12:00');
-      const zdt = date.toZonedDateTime('America/Los_Angeles', time);
+      const zdt = date.toZonedDateTime({ timeZone: 'America/Los_Angeles', time });
       equal(`${zdt}`, '2020-07-08T12:00:00-07:00[America/Los_Angeles]');
     });
-    it('casts second argument', () => {
+    it('casts time property', () => {
       const date = PlainDate.from('2020-07-08');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      const zdt = date.toZonedDateTime(tz, '12:00');
+      const zdt = date.toZonedDateTime({ timeZone: tz, time: '12:00' });
       equal(`${zdt}`, '2020-07-08T12:00:00-07:00[America/Los_Angeles]');
     });
-    it('throws on bad disambiguation', () => {
-      ['', 'EARLIER', 'xyz', 3, null].forEach((disambiguation) =>
-        throws(() => PlainDate.from('2019-10-29').toZonedDateTime('UTC', '12:00', { disambiguation }), RangeError)
-      );
-    });
-    it('options may only be an object or undefined', () => {
-      const date = PlainDate.from('2019-10-29');
-      [null, 1, 'hello', true, Symbol('foo'), 1n].forEach((badOptions) =>
-        throws(() => date.toZonedDateTime('America/Sao_Paulo', '10:46:38', badOptions), TypeError)
-      );
-      [{}, () => {}, undefined].forEach((options) =>
-        equal(
-          `${date.toZonedDateTime('America/Sao_Paulo', '10:46:38', options)}`,
-          '2019-10-29T10:46:38-03:00[America/Sao_Paulo]'
-        )
-      );
-    });
   });
   describe('date.until() works', () => {
     const date = new PlainDate(1969, 7, 24);
diff --git a/polyfill/test/plaintime.mjs b/polyfill/test/plaintime.mjs
index 5c653303ad..a0bc772af2 100644
--- a/polyfill/test/plaintime.mjs
+++ b/polyfill/test/plaintime.mjs
@@ -268,44 +268,21 @@ describe('Time', () => {
       const time = PlainTime.from('12:00');
       const date = Temporal.PlainDate.from('2020-01-01');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      equal(`${time.toZonedDateTime(tz, date)}`, '2020-01-01T12:00:00-08:00[America/Los_Angeles]');
+      const zdt = time.toZonedDateTime({ timeZone: tz, date });
+      equal(`${zdt}`, '2020-01-01T12:00:00-08:00[America/Los_Angeles]');
     });
-    it('works with disambiguation option', () => {
-      const time = PlainTime.from('02:00');
-      const date = Temporal.PlainDate.from('2020-03-08');
-      const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      const zdt = time.toZonedDateTime(tz, date, { disambiguation: 'earlier' });
-      equal(`${zdt}`, '2020-03-08T01:00:00-08:00[America/Los_Angeles]');
-    });
-    it('casts first argument', () => {
+    it('casts timeZone property', () => {
       const time = PlainTime.from('12:00');
       const date = Temporal.PlainDate.from('2020-07-08');
-      const zdt = time.toZonedDateTime('America/Los_Angeles', date);
+      const zdt = time.toZonedDateTime({ timeZone: 'America/Los_Angeles', date });
       equal(`${zdt}`, '2020-07-08T12:00:00-07:00[America/Los_Angeles]');
     });
-    it('casts second argument', () => {
+    it('casts date property', () => {
       const time = PlainTime.from('12:00');
       const tz = Temporal.TimeZone.from('America/Los_Angeles');
-      const zdt = time.toZonedDateTime(tz, '2020-07-08');
+      const zdt = time.toZonedDateTime({ timeZone: tz, date: '2020-07-08' });
       equal(`${zdt}`, '2020-07-08T12:00:00-07:00[America/Los_Angeles]');
     });
-    it('throws on bad disambiguation', () => {
-      ['', 'EARLIER', 'xyz', 3, null].forEach((disambiguation) =>
-        throws(() => PlainTime.from('12:00').toZonedDateTime('UTC', '2019-10-29', { disambiguation }), RangeError)
-      );
-    });
-    it('options may only be an object or undefined', () => {
-      const time = PlainTime.from('10:46:38');
-      [null, 1, 'hello', true, Symbol('foo'), 1n].forEach((badOptions) =>
-        throws(() => time.toZonedDateTime('America/Sao_Paulo', '2019-10-29', badOptions), TypeError)
-      );
-      [{}, () => {}, undefined].forEach((options) =>
-        equal(
-          `${time.toZonedDateTime('America/Sao_Paulo', '2019-10-29', options)}`,
-          '2019-10-29T10:46:38-03:00[America/Sao_Paulo]'
-        )
-      );
-    });
   });
   describe('time.until() works', () => {
     const time = new PlainTime(15, 23, 30, 123, 456, 789);
diff --git a/spec/plaindate.html b/spec/plaindate.html
index c4647f67d0..7e8155c97c 100644
--- a/spec/plaindate.html
+++ b/spec/plaindate.html
@@ -523,23 +523,33 @@ <h1>Temporal.PlainDate.prototype.toPlainDateTime ( [ _temporalTime_ ] )</h1>
     </emu-clause>
 
     <emu-clause id="sec-temporal.date.prototype.tozoneddatetime">
-      <h1>Temporal.PlainDate.prototype.toZonedDateTime ( _timeZoneLike_ [ , _temporalTime_ [ , _options_ ] ] )</h1>
+      <h1>Temporal.PlainDate.prototype.toZonedDateTime ( _item_ )</h1>
       <p>
-        The `toZonedDateTime` method takes three arguments, _timeZoneLike_, _temporalTime_, and _options_.
+        The `toZonedDateTime` method takes one argument _item_.
         The following steps are taken:
       </p>
       <emu-alg>
         1. Let _temporalDate_ be the *this* value.
         1. Perform ? RequireInternalSlot(_temporalDate_, [[InitializedTemporalDate]]).
-        1. Let _timeZone_ be ? ToTemporalTimeZone(_temporalTimeZoneLike_).
-        1. Set _options_ to ? NormalizeOptionsObject(_options_).
-        1. Let _disambiguation_ be ? ToTemporalDisambiguation(_options_).
+        1. If Type(_item_) is Object, then
+          1. Let _timeZoneLike_ be ? Get(_item_, *"timeZone"*).
+          1. If _timeZoneLike_ is *undefined*, then
+            <!-- Treat _item_ itself as a TimeZone -->
+            1. Let _timeZone_ be ? ToTemporalTimeZone(_item_).
+            1. Let _temporalTime_ be *undefined*.
+          1. Else,
+            <!-- Treat _item_ as a property bag -->
+            1. Let _timeZone_ be ? ToTemporalTimeZone(_timeZoneLike_).
+            1. Let _temporalTime_ be ? Get(_item_, *"time"*).
+        1. Else,
+          1. Let _timeZone_ be ? ToTemporalTimeZone(_item_).
+          1. Let _temporalTime_ be *undefined*.
         1. If _temporalTime_ is *undefined*, then
           1. Let _temporalDateTime_ be ? CreateTemporalDateTime(_temporalDate_.[[ISOYear]], _temporalDate_.[[ISOMonth]], _temporalDate_.[[ISODay]], 0, 0, 0, 0, 0, 0, _temporalDate_.[[Calendar]]).
         1. Else,
           1. Set _temporalTime_ to ? ToTemporalTime(_temporalTime_).
           1. Let _temporalDateTime_ be ? CreateTemporalDateTime(_temporalDate_.[[ISOYear]], _temporalDate_.[[ISOMonth]], _temporalDate_.[[ISODay]], _temporalTime_.[[Hour]], _temporalTime_.[[Minute]], _temporalTime_.[[Second]], _temporalTime_.[[Millisecond]], _temporalTime_.[[Microsecond]], _temporalTime_.[[Nanosecond]], _temporalDate_.[[Calendar]]).
-        1. Let _instant_ be ? GetTemporalInstantFor(_timeZone_, _temporalDateTime_, _disambiguation_).
+        1. Let _instant_ be ? GetTemporalInstantFor(_timeZone_, _temporalDateTime_, *"compatible"*).
         1. Return ? CreateTemporalZonedDateTime(_instant_.[[Nanoseconds]], _timeZone_, _temporalDate_.[[Calendar]]).
       </emu-alg>
     </emu-clause>
diff --git a/spec/plaintime.html b/spec/plaintime.html
index c647307427..822466d2b9 100644
--- a/spec/plaintime.html
+++ b/spec/plaintime.html
@@ -404,20 +404,24 @@ <h1>Temporal.PlainTime.prototype.toPlainDateTime ( _temporalDate_ )</h1>
     </emu-clause>
 
     <emu-clause id="sec-temporal.time.prototype.tozoneddatetime">
-      <h1>Temporal.PlainTime.prototype.toZonedDateTime ( _timeZoneLike_, _temporalDate_ [ , _options_ ] )</h1>
+      <h1>Temporal.PlainTime.prototype.toZonedDateTime ( _item_ )</h1>
       <p>
-        The `toZonedDateTime` method takes three arguments, _timeZoneLike_, _temporalDate_, and _options_.
+        The `toZonedDateTime` method takes one argument _item_.
         The following steps are taken:
       </p>
       <emu-alg>
         1. Let _temporalTime_ be the *this* value.
         1. Perform ? RequireInternalSlot(_temporalTime_, [[InitializedTemporalTime]]).
+        1. Let _temporalDateLike_ be ? Get(_item_, *"date"*).
+        1. If _temporalDateLike_ is *undefined*, then
+          1. Throw a *TypeError* exception.
+        1. Let _temporalDate_ to ? ToTemporalTime(_temporalDateLike_).
+        1. Let _temporalTimeZoneLike_ be ? Get(_item_, *"timeZone"*).
+        1. If _temporalTimeZoneLike_ is *undefined*, then
+          1. Throw a *TypeError* exception.
         1. Let _timeZone_ be ? ToTemporalTimeZone(_temporalTimeZoneLike_).
-        1. Set _temporalDate_ to ? ToTemporalTime(_temporalDate_).
-        1. Set _options_ to ? NormalizeOptionsObject(_options_).
-        1. Let _disambiguation_ be ? ToTemporalDisambiguation(_options_).
         1. Let _temporalDateTime_ be ? CreateTemporalDateTime(_temporalDate_.[[ISOYear]], _temporalDate_.[[ISOMonth]], _temporalDate_.[[ISODay]], _temporalTime_.[[Hour]], _temporalTime_.[[Minute]], _temporalTime_.[[Second]], _temporalTime_.[[Millisecond]], _temporalTime_.[[Microsecond]], _temporalTime_.[[Nanosecond]], _temporalDate_.[[Calendar]]).
-        1. Let _instant_ be ? GetTemporalInstantFor(_timeZone_, _temporalDateTime_, _disambiguation_).
+        1. Let _instant_ be ? GetTemporalInstantFor(_timeZone_, _temporalDateTime_, *"compatible"*).
         1. Return ? CreateTemporalZonedDateTime(_instant_.[[Nanoseconds]], _timeZone_, _temporalDate_.[[Calendar]]).
       </emu-alg>
     </emu-clause>