diff --git a/polyfill/lib/ecmascript.mjs b/polyfill/lib/ecmascript.mjs
index 581beeb67..079b56dce 100644
--- a/polyfill/lib/ecmascript.mjs
+++ b/polyfill/lib/ecmascript.mjs
@@ -1363,7 +1363,7 @@ export function ToTemporalInstant(item) {
 
   // ParseTemporalInstantString ensures that either `z` is true or or `offset` is non-undefined
   const offsetNanoseconds = z ? 0 : ParseDateTimeUTCOffset(offset);
-  const epochNanoseconds = GetUTCEpochNanoseconds(
+  const balanced = BalanceISODateTime(
     year,
     month,
     day,
@@ -1372,8 +1372,22 @@ export function ToTemporalInstant(item) {
     second,
     millisecond,
     microsecond,
-    nanosecond
-  ).subtract(offsetNanoseconds);
+    nanosecond - offsetNanoseconds
+  );
+  if (MathAbs(ISODateToEpochDays(balanced.year, balanced.month - 1, balanced.day)) > 1e8) {
+    throw new RangeErrorCtor('date/time value is outside the supported range');
+  }
+  const epochNanoseconds = GetUTCEpochNanoseconds(
+    balanced.year,
+    balanced.month,
+    balanced.day,
+    balanced.hour,
+    balanced.minute,
+    balanced.second,
+    balanced.millisecond,
+    balanced.microsecond,
+    balanced.nanosecond
+  );
   ValidateEpochNanoseconds(epochNanoseconds);
   return new TemporalInstant(epochNanoseconds);
 }
diff --git a/spec/instant.html b/spec/instant.html
index 3ea349fe1..22a91e0b0 100644
--- a/spec/instant.html
+++ b/spec/instant.html
@@ -412,12 +412,13 @@ <h1>
         1. Let _parsed_ be ? ParseISODateTime(_item_, « |TemporalInstantString| »).
         1. Assert: Either _parsed_.[[TimeZone]].[[OffsetString]] is not ~empty~ or _parsed_.[[TimeZone]].[[Z]] is *true*, but not both.
         1. If _parsed_.[[TimeZone]].[[Z]] is *true*, let _offsetNanoseconds_ be 0; otherwise, let _offsetNanoseconds_ be ! ParseDateTimeUTCOffset(_parsed_.[[TimeZone]].[[OffsetString]]).
-        1. If abs(ISODateToEpochDays(_parsed_.[[Year]], _parsed_.[[Month]] - 1, _parsed_.[[Day]])) > 10<sup>8</sup>, throw a *RangeError* exception.
         1. If _parsed_.[[Time]] is ~start-of-day~, then
           1. Let _time_ be Time Record { [[Days]]: 0, [[Hour]]: 0, [[Minute]]: 0, [[Second]]: 0, [[Millisecond]]: 0, [[Microsecond]]: 0, [[Nanosecond]]: 0 }.
         1. Else,
           1. Let _time_ be _parsed_.[[Time]].
-        1. Let _epochNanoseconds_ be GetUTCEpochNanoseconds(_parsed_.[[Year]], _parsed_.[[Month]], _parsed_.[[Day]], _time_.[[Hour]], _time_.[[Minute]], _time_.[[Second]], _time_.[[Millisecond]], _time_.[[Microsecond]], _time_.[[Nanosecond]]) - ℤ(_offsetNanoseconds_).
+        1. Let _balanced_ be BalanceISODateTime(_parsed_.[[Year]], _parsed_.[[Month]], _parsed_.[[Day]], _time_.[[Hour]], _time_.[[Minute]], _time_.[[Second]], _time_.[[Millisecond]], _time_.[[Microsecond]], _time_.[[Nanosecond]] - _offsetNanoseconds_).
+        1. If abs(ISODateToEpochDays(_balanced_.[[Year]], _balanced_.[[Month]] - 1, _balanced_.[[Day]])) > 10<sup>8</sup>, throw a *RangeError* exception.
+        1. Let _epochNanoseconds_ be GetUTCEpochNanoseconds(_balanced_.[[Year]], _balanced_.[[Month]], _balanced_.[[Day]], _balanced_.[[Hour]], _balanced_.[[Minute]], _balanced_.[[Second]], _balanced_.[[Millisecond]], _balanced_.[[Microsecond]], _balanced_.[[Nanosecond]]).
         1. If IsValidEpochNanoseconds(_epochNanoseconds_) is *false*, throw a *RangeError* exception.
         1. Return ! CreateTemporalInstant(_epochNanoseconds_).
       </emu-alg>