diff --git a/polyfill/lib/civildate.mjs b/polyfill/lib/civildate.mjs
index d460f23bee..dcd6f3b6d5 100644
--- a/polyfill/lib/civildate.mjs
+++ b/polyfill/lib/civildate.mjs
@@ -28,10 +28,13 @@ export class CivilDate {
   withTime(time) {
     return new CivilDateTime.from(this, time);
   }
-  toString() {
+  asString() {
     const { year, month, day } = this;
     return `${spad(year, 4)}-${pad(month, 2)}-${pad(day, 2)}`;
   }
+  toString() {
+    return `[object CivilDate ${this.asString()}]`;
+  }
 
   static fromString(string) {
     const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(string);
diff --git a/polyfill/lib/civildatetime.mjs b/polyfill/lib/civildatetime.mjs
index b5f7ca660b..acc6611964 100644
--- a/polyfill/lib/civildatetime.mjs
+++ b/polyfill/lib/civildatetime.mjs
@@ -48,10 +48,13 @@ export class CivilDateTime {
     instant[VALUE] = { milliseconds, nanoseconds };
     return new ZonedInstant(instant, zone);
   }
-  toString() {
+  asString() {
     const { year, month, day, hour, minute, second, millisecond, nanosecond } = this;
     return `${spad(year, 4)}-${pad(month, 2)}-${pad(day, 2)}T${pad(hour, 2)}:${pad(minute, 2)}:${pad(second, 2)}.${pad(millisecond,3)}${pad(nanosecond, 6)}`;
   }
+  toString() {
+    return `[object CivilDateTime ${this.asString()}]`;
+  }
 
   static fromString(string) {
     const match = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})(\d{6})$/.exec(string);
diff --git a/polyfill/lib/civiltime.mjs b/polyfill/lib/civiltime.mjs
index 829cc7bca9..ac07a094be 100644
--- a/polyfill/lib/civiltime.mjs
+++ b/polyfill/lib/civiltime.mjs
@@ -37,10 +37,13 @@ export class CivilTime {
   withDate(date) {
     return new CivilDateTime.from(date, this);
   }
-  toString() {
+  asString() {
     const { hour, minute, second, millisecond, nanosecond } = this;
     return `${pad(hour, 2)}:${pad(minute, 2)}:${pad(second, 2)}.${pad(millisecond, 3)}${pad(nanosecond, 6)}`;
   }
+  toString() {
+    return `[object CivilTime ${this.asString()}]`;
+  }
 
   static fromString(string) {
     const match = /^(\d{2}):(\d{2}):(\d{2})\.(\d{3})(\d{6})$/.exec(string);
diff --git a/polyfill/lib/instant.mjs b/polyfill/lib/instant.mjs
index f37aa8d982..2f88065616 100644
--- a/polyfill/lib/instant.mjs
+++ b/polyfill/lib/instant.mjs
@@ -37,11 +37,14 @@ export class Instant {
   format(locale, options) {
     return this.withZone().format(locale, options);
   }
-  toString() {
+  asString() {
     const { year, month, day, hour, minute, second, millisecond } = fromEpoch(this.milliseconds, 'UTC');
     const nanosecond = this.nanoseconds;
     return `${spad(year,4)}-${pad(month,2)}-${pad(day,2)}T${pad(hour,2)}:${pad(minute,2)}:${pad(second,2)}.${pad(millisecond,3)}${pad(nanosecond,6)}Z`;
   }
+  toString() {
+    return `[object Instant ${this.asString()}]`;
+  }
 
   static fromString(string) {
     const match = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})(\d{6})Z$/.exec(string);
diff --git a/polyfill/lib/zonedinstant.mjs b/polyfill/lib/zonedinstant.mjs
index 20123fad96..8e5d1752a8 100644
--- a/polyfill/lib/zonedinstant.mjs
+++ b/polyfill/lib/zonedinstant.mjs
@@ -47,13 +47,16 @@ export class ZonedInstant{
     );
     return fmt.format(new Date(this.toInstant().milliseconds));
   }
-  toString() {
+  asString() {
     const ts = this[INSTANT].milliseconds;
     const { year, month, day, hour, minute, second, millisecond } = fromEpoch(ts, this[ZONE]);
     const nanosecond = this[INSTANT].nanoseconds;
     const offset = ([ 'UTC', '+00:00', '-00:00' ].indexOf(this[ZONE]) > -1) ? 'Z' : zoneOffset(ts, this[ZONE]);
     return `${spad(year,4)}-${pad(month,2)}-${pad(day,2)}T${pad(hour,2)}:${pad(minute,2)}:${pad(second,2)}.${pad(millisecond,3)}${pad(nanosecond,6)}${offset}`;
   }
+  toString() {
+    return `[object ZonedInstant ${this.asString()}]`;
+  }
 
   static fromString(string) {
     const match = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})(\d{6})(Z|[+-]\d{2}:\d{2})$/.exec(string);
diff --git a/polyfill/test/compat/civildate.js b/polyfill/test/compat/civildate.js
index 2946343efa..70d45a9255 100644
--- a/polyfill/test/compat/civildate.js
+++ b/polyfill/test/compat/civildate.js
@@ -15,7 +15,8 @@ test('CivilDate', ({ test, end })=>{
     equal(instance.second, undefined);
     equal(instance.millisecond, undefined);
     equal(instance.nanosecond, undefined);
-    equal(instance.toString(), '1976-11-18');
+    equal(instance.asString(), '1976-11-18');
+    equal(instance.toString(), '[object CivilDate 1976-11-18]');
 
     end();
   });
diff --git a/polyfill/test/compat/civildatetime.js b/polyfill/test/compat/civildatetime.js
index 573783d1b5..3ce4e48a08 100644
--- a/polyfill/test/compat/civildatetime.js
+++ b/polyfill/test/compat/civildatetime.js
@@ -4,38 +4,39 @@ const { CivilDateTime } = require('../../');
 test('CivilDateTime', ({ test, end })=>{
   test('simple', ({ equal, end })=>{
     const instance = new CivilDateTime(1976, 11, 18, 15, 23, 30);
+    equal('[object CivilDateTime 1976-11-18T15:23:30.000000000]', instance.toString());
 
-    equal('1976-11-18T15:23:30.000000000', instance.toString());
-    equal('1976-11-18T15:23:30.000000000+01:00', instance.withZone('Europe/Berlin').toString());
+    equal('1976-11-18T15:23:30.000000000', instance.asString());
+    equal('1976-11-18T15:23:30.000000000+01:00', instance.withZone('Europe/Berlin').asString());
 
     const anniversary = instance.plus({ years: 3 });
-    equal('1979-11-18T15:23:30.000000000', anniversary.toString());
-    equal('1979-11-18T15:23:30.000000000+01:00', anniversary.withZone('Europe/Berlin').toString());
+    equal('1979-11-18T15:23:30.000000000', anniversary.asString());
+    equal('1979-11-18T15:23:30.000000000+01:00', anniversary.withZone('Europe/Berlin').asString());
 
     const runup = anniversary.plus({ months: -1 });
-    equal('1979-10-18T15:23:30.000000000', runup.toString());
-    equal('1979-10-18T15:23:30.000000000+01:00', runup.withZone('Europe/Berlin').toString());
+    equal('1979-10-18T15:23:30.000000000', runup.asString());
+    equal('1979-10-18T15:23:30.000000000+01:00', runup.withZone('Europe/Berlin').asString());
 
     const thirty = runup.plus({ days: 30 });
-    equal('1979-11-17T15:23:30.000000000', thirty.toString());
-    equal('1979-11-17T15:23:30.000000000+01:00', thirty.withZone('Europe/Berlin').toString());
+    equal('1979-11-17T15:23:30.000000000', thirty.asString());
+    equal('1979-11-17T15:23:30.000000000+01:00', thirty.withZone('Europe/Berlin').asString());
 
     const preptime = anniversary.plus({ hours: -5, minutes: 37, seconds: 30, milliseconds: 4, nanoseconds: -3 });
-    equal('1979-11-18T11:01:00.003999997', preptime.toString());
-    equal('1979-11-18T11:01:00.003999997+01:00', preptime.withZone('Europe/Berlin').toString());
+    equal('1979-11-18T11:01:00.003999997', preptime.asString());
+    equal('1979-11-18T11:01:00.003999997+01:00', preptime.withZone('Europe/Berlin').asString());
 
     const daybreak = anniversary.with({ hour: 0, minute: 0, second: 0 });
-    equal('1979-11-18T00:00:00.000000000', daybreak.toString());
-    equal('1979-11-18T00:00:00.000000000+01:00', daybreak.withZone('Europe/Berlin').toString());
+    equal('1979-11-18T00:00:00.000000000', daybreak.asString());
+    equal('1979-11-18T00:00:00.000000000+01:00', daybreak.withZone('Europe/Berlin').asString());
 
     const nightfall = anniversary.with({ hour: 23, minute: 59, second: 59, millisecond: 1000, nanosecond: -1 });
-    equal('1979-11-18T23:59:59.999999999', nightfall.toString());
-    equal('1979-11-18T23:59:59.999999999+01:00', nightfall.withZone('Europe/Berlin').toString());
+    equal('1979-11-18T23:59:59.999999999', nightfall.asString());
+    equal('1979-11-18T23:59:59.999999999+01:00', nightfall.withZone('Europe/Berlin').asString());
 
     const year = (new Date()).getFullYear()
     const birthday = instance.with({ year });
-    equal(`${year}-11-18T15:23:30.000000000`, birthday.toString());
-    equal(`${year}-11-18T15:23:30.000000000+01:00`, birthday.withZone('Europe/Berlin').toString());
+    equal(`${year}-11-18T15:23:30.000000000`, birthday.asString());
+    equal(`${year}-11-18T15:23:30.000000000+01:00`, birthday.withZone('Europe/Berlin').asString());
 
     end();
   });
@@ -53,7 +54,7 @@ test('CivilDateTime', ({ test, end })=>{
     equal(instance.second, 30);
     equal(instance.millisecond, 450);
     equal(instance.nanosecond, 12345);
-    equal(instance.toString(), '1976-11-18T15:23:30.450012345');
+    equal(instance.asString(), '1976-11-18T15:23:30.450012345');
 
     end();
   });
diff --git a/polyfill/test/compat/civiltime.js b/polyfill/test/compat/civiltime.js
index f63c01866b..90ddd337db 100644
--- a/polyfill/test/compat/civiltime.js
+++ b/polyfill/test/compat/civiltime.js
@@ -15,7 +15,8 @@ test('CivilTime', ({ test, end })=>{
     equal(instance.second, 30);
     equal(instance.millisecond, 450);
     equal(instance.nanosecond, 12345);
-    equal(instance.toString(), '15:23:30.450012345');
+    equal(instance.asString(), '15:23:30.450012345');
+    equal(instance.toString(), '[object CivilTime 15:23:30.450012345]');
 
     end();
   });
diff --git a/polyfill/test/compat/instant.js b/polyfill/test/compat/instant.js
index 43da020fde..2dff71726d 100644
--- a/polyfill/test/compat/instant.js
+++ b/polyfill/test/compat/instant.js
@@ -5,11 +5,12 @@ test('Instant', ({ test, end})=>{
   test('simple', ({ equal, end })=>{
     const instant = Instant.fromMilliseconds(0);
 
-    equal('1970-01-01T00:00:00.000000000Z', instant.toString());
+    equal('[object Instant 1970-01-01T00:00:00.000000000Z]', instant.toString());
+    equal('1970-01-01T00:00:00.000000000Z', instant.asString());
 
     const now = new Date();
     const nowi = Instant.fromMilliseconds(now);
-    equal(now.toISOString().replace('Z','000000Z'), nowi.toString());
+    equal(now.toISOString().replace('Z','000000Z'), nowi.asString());
     end();
   });
 
@@ -20,7 +21,7 @@ test('Instant', ({ test, end})=>{
     equal(instance instanceof Instant, true);
     equal(instance.milliseconds, 217178610450);
     equal(instance.nanoseconds, 0);
-    equal(instance.toString(), '1976-11-18T15:23:30.450000000Z');
+    equal(instance.asString(), '1976-11-18T15:23:30.450000000Z');
 
     end();
   });
diff --git a/polyfill/test/compat/zonedinstant.js b/polyfill/test/compat/zonedinstant.js
index f85a3c24c2..8a45afa738 100644
--- a/polyfill/test/compat/zonedinstant.js
+++ b/polyfill/test/compat/zonedinstant.js
@@ -15,7 +15,8 @@ test('ZonedInstant', ({ test, end})=>{
     equal(instance instanceof ZonedInstant, true);
     equal(instance.milliseconds, 217175010450);
     equal(instance.nanoseconds, 0);
-    equal(instance.toString(), '1976-11-18T15:23:30.450000000+01:00');
+    equal(instance.asString(), '1976-11-18T15:23:30.450000000+01:00');
+    equal(instance.toString(), '[object ZonedInstant 1976-11-18T15:23:30.450000000+01:00]');
     end();
   });
 
diff --git a/polyfill/test/temporal/CivilDate/constructor.js b/polyfill/test/temporal/CivilDate/constructor.js
index 644c53c5c6..bbf33532ef 100644
--- a/polyfill/test/temporal/CivilDate/constructor.js
+++ b/polyfill/test/temporal/CivilDate/constructor.js
@@ -20,4 +20,5 @@ assert.sameValue(instance.minute, undefined);
 assert.sameValue(instance.second, undefined);
 assert.sameValue(instance.millisecond, undefined);
 assert.sameValue(instance.nanosecond, undefined);
-assert.sameValue(instance.toString(), '1976-11-18');
+assert.sameValue(instance.asString(), '1976-11-18');
+assert.sameValue(instance.toString(), '[object CivilDate 1976-11-18]');
diff --git a/polyfill/test/temporal/CivilDateTime/basic.js b/polyfill/test/temporal/CivilDateTime/basic.js
index 255433f62f..34f6c76c46 100644
--- a/polyfill/test/temporal/CivilDateTime/basic.js
+++ b/polyfill/test/temporal/CivilDateTime/basic.js
@@ -10,34 +10,36 @@ esid: pending
 
 const instance = new temporal.CivilDateTime(1976, 11, 18, 15, 23, 30);
 
-assert.sameValue('1976-11-18T15:23:30.000000000', instance.toString());
-assert.sameValue('1976-11-18T15:23:30.000000000+01:00', instance.withZone('Europe/Berlin').toString());
+assert.sameValue('[object CivilDateTime 1976-11-18T15:23:30.000000000]', instance.toString());
+
+assert.sameValue('1976-11-18T15:23:30.000000000', instance.asString());
+assert.sameValue('1976-11-18T15:23:30.000000000+01:00', instance.withZone('Europe/Berlin').asString());
 
 const anniversary = instance.plus({ years: 3 });
-assert.sameValue('1979-11-18T15:23:30.000000000', anniversary.toString());
-assert.sameValue('1979-11-18T15:23:30.000000000+01:00', anniversary.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-11-18T15:23:30.000000000', anniversary.asString());
+assert.sameValue('1979-11-18T15:23:30.000000000+01:00', anniversary.withZone('Europe/Berlin').asString());
 
 const runup = anniversary.plus({ months: -1 });
-assert.sameValue('1979-10-18T15:23:30.000000000', runup.toString());
-assert.sameValue('1979-10-18T15:23:30.000000000+01:00', runup.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-10-18T15:23:30.000000000', runup.asString());
+assert.sameValue('1979-10-18T15:23:30.000000000+01:00', runup.withZone('Europe/Berlin').asString());
 
 const thirty = runup.plus({ days: 30 });
-assert.sameValue('1979-11-17T15:23:30.000000000', thirty.toString());
-assert.sameValue('1979-11-17T15:23:30.000000000+01:00', thirty.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-11-17T15:23:30.000000000', thirty.asString());
+assert.sameValue('1979-11-17T15:23:30.000000000+01:00', thirty.withZone('Europe/Berlin').asString());
 
 const preptime = anniversary.plus({ hours: -5, minutes: 37, seconds: 30, milliseconds: 4, nanoseconds: -3 });
-assert.sameValue('1979-11-18T11:01:00.003999997', preptime.toString());
-assert.sameValue('1979-11-18T11:01:00.003999997+01:00', preptime.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-11-18T11:01:00.003999997', preptime.asString());
+assert.sameValue('1979-11-18T11:01:00.003999997+01:00', preptime.withZone('Europe/Berlin').asString());
 
 const daybreak = anniversary.with({ hour: 0, minute: 0, second: 0 });
-assert.sameValue('1979-11-18T00:00:00.000000000', daybreak.toString());
-assert.sameValue('1979-11-18T00:00:00.000000000+01:00', daybreak.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-11-18T00:00:00.000000000', daybreak.asString());
+assert.sameValue('1979-11-18T00:00:00.000000000+01:00', daybreak.withZone('Europe/Berlin').asString());
 
 const nightfall = anniversary.with({ hour: 23, minute: 59, second: 59, millisecond: 1000, nanosecond: -1 });
-assert.sameValue('1979-11-18T23:59:59.999999999', nightfall.toString());
-assert.sameValue('1979-11-18T23:59:59.999999999+01:00', nightfall.withZone('Europe/Berlin').toString());
+assert.sameValue('1979-11-18T23:59:59.999999999', nightfall.asString());
+assert.sameValue('1979-11-18T23:59:59.999999999+01:00', nightfall.withZone('Europe/Berlin').asString());
 
 const year = (new Date()).getFullYear()
 const birthday = instance.with({ year });
-assert.sameValue(`${year}-11-18T15:23:30.000000000`, birthday.toString());
-assert.sameValue(`${year}-11-18T15:23:30.000000000+01:00`, birthday.withZone('Europe/Berlin').toString());
+assert.sameValue(`${year}-11-18T15:23:30.000000000`, birthday.asString());
+assert.sameValue(`${year}-11-18T15:23:30.000000000+01:00`, birthday.withZone('Europe/Berlin').asString());
diff --git a/polyfill/test/temporal/CivilDateTime/constructor.js b/polyfill/test/temporal/CivilDateTime/constructor.js
index 7ee4eac3d2..8a01dde20b 100644
--- a/polyfill/test/temporal/CivilDateTime/constructor.js
+++ b/polyfill/test/temporal/CivilDateTime/constructor.js
@@ -20,4 +20,5 @@ assert.sameValue(instance.minute, 23);
 assert.sameValue(instance.second, 30);
 assert.sameValue(instance.millisecond, 450);
 assert.sameValue(instance.nanosecond, 12345);
-assert.sameValue(instance.toString(), '1976-11-18T15:23:30.450012345');
+assert.sameValue(instance.asString(), '1976-11-18T15:23:30.450012345');
+assert.sameValue(instance.toString(), '[object CivilDateTime 1976-11-18T15:23:30.450012345]');
diff --git a/polyfill/test/temporal/CivilTime/constructor.js b/polyfill/test/temporal/CivilTime/constructor.js
index f81e8c72e7..d6409bb194 100644
--- a/polyfill/test/temporal/CivilTime/constructor.js
+++ b/polyfill/test/temporal/CivilTime/constructor.js
@@ -20,4 +20,5 @@ assert.sameValue(instance.minute, 23);
 assert.sameValue(instance.second, 30);
 assert.sameValue(instance.millisecond, 450);
 assert.sameValue(instance.nanosecond, 12345);
-assert.sameValue(instance.toString(), '15:23:30.450012345');
+assert.sameValue(instance.asString(), '15:23:30.450012345');
+assert.sameValue(instance.toString(), '[object CivilTime 15:23:30.450012345]');
diff --git a/polyfill/test/temporal/Instant/basic.js b/polyfill/test/temporal/Instant/basic.js
index 724d9745ce..2d3505e9e5 100644
--- a/polyfill/test/temporal/Instant/basic.js
+++ b/polyfill/test/temporal/Instant/basic.js
@@ -9,9 +9,10 @@ esid: pending
 ---*/
 
 const instant = new temporal.Instant(0n);
+assert.sameValue('[object Instant 1970-01-01T00:00:00.000000000Z]', instant.toString());
 
-assert.sameValue('1970-01-01T00:00:00.000000000Z', instant.toString());
+assert.sameValue('1970-01-01T00:00:00.000000000Z', instant.asString());
 
 const now = new Date();
 const nowi = new temporal.Instant(BigInt(now.valueOf()) * BigInt(1e6));
-assert.sameValue(now.toISOString().replace('Z','000000Z'), nowi.toString());
+assert.sameValue(now.toISOString().replace('Z','000000Z'), nowi.asString());
diff --git a/polyfill/test/temporal/Instant/constructor.js b/polyfill/test/temporal/Instant/constructor.js
index 1db0049ed3..30a3b52c5f 100644
--- a/polyfill/test/temporal/Instant/constructor.js
+++ b/polyfill/test/temporal/Instant/constructor.js
@@ -15,4 +15,5 @@ assert.sameValue(instance instanceof temporal.Instant, true);
 assert.sameValue(instance.milliseconds, 217178610450);
 assert.sameValue(instance.nanoseconds, 100);
 assert.sameValue(instance.value, 217178610450000100n);
-assert.sameValue(instance.toString(), '1976-11-18T15:23:30.450000100Z');
+assert.sameValue(instance.asString(), '1976-11-18T15:23:30.450000100Z');
+assert.sameValue(instance.toString(), '[object Instant 1976-11-18T15:23:30.450000100Z]');
diff --git a/polyfill/test/temporal/ZonedInstant/constructor.js b/polyfill/test/temporal/ZonedInstant/constructor.js
index b0b369f85a..fe11cb0fb5 100644
--- a/polyfill/test/temporal/ZonedInstant/constructor.js
+++ b/polyfill/test/temporal/ZonedInstant/constructor.js
@@ -16,7 +16,8 @@ assert.sameValue(one instanceof temporal.ZonedInstant, true);
 assert.sameValue(one.milliseconds, 217175010450);
 assert.sameValue(one.nanoseconds, 100);
 assert.sameValue(one.value, 217175010450000100n);
-assert.sameValue(one.toString(), '1976-11-18T15:23:30.450000100+01:00');
+assert.sameValue(one.asString(), '1976-11-18T15:23:30.450000100+01:00');
+assert.sameValue(one.toString(), '[object ZonedInstant 1976-11-18T15:23:30.450000100+01:00]');
 
 const two = new temporal.ZonedInstant(instant, 'America/New_York');
 assert.sameValue(typeof two, 'object');
@@ -24,4 +25,5 @@ assert.sameValue(two instanceof temporal.ZonedInstant, true);
 assert.sameValue(two.milliseconds, 217175010450);
 assert.sameValue(two.nanoseconds, 100);
 assert.sameValue(two.value, 217175010450000100n);
-assert.sameValue(two.toString(), '1976-11-18T09:23:30.450000100-05:00');
+assert.sameValue(two.asString(), '1976-11-18T09:23:30.450000100-05:00');
+assert.sameValue(two.toString(), '[object ZonedInstant 1976-11-18T09:23:30.450000100-05:00]');