diff --git a/src/builtins/builtins-temporal.cc b/src/builtins/builtins-temporal.cc
index 7f9deff2f8..1b3238d2ca 100644
--- a/src/builtins/builtins-temporal.cc
+++ b/src/builtins/builtins-temporal.cc
@@ -328,8 +328,6 @@ TO_BE_IMPLEMENTED(TemporalCalendarPrototypeWeekOfYear)
 TO_BE_IMPLEMENTED(TemporalCalendarPrototypeDaysInWeek)
 /* Temporal #sec-temporal.calendar.prototype.daysinmonth */
 TO_BE_IMPLEMENTED(TemporalCalendarPrototypeDaysInMonth)
-/* Temporal #sec-temporal.calendar.prototype.inleapyear */
-TO_BE_IMPLEMENTED(TemporalCalendarPrototypeInLeapYear)
 /* Temporal #sec-temporal.calendar.prototype.mergefields */
 TO_BE_IMPLEMENTED(TemporalCalendarPrototypeMergeFields)
 /* Temporal #sec-temporal.calendar.prototype.tojson */
@@ -799,6 +797,7 @@ TEMPORAL_PROTOTYPE_METHOD1(Calendar, DaysInYear, daysInYear)
 TEMPORAL_PROTOTYPE_METHOD1(Calendar, DayOfWeek, dayOfWeek)
 TEMPORAL_PROTOTYPE_METHOD1(Calendar, DayOfYear, dayOfYear)
 TEMPORAL_PROTOTYPE_METHOD1(Calendar, MonthsInYear, monthsInYear)
+TEMPORAL_PROTOTYPE_METHOD1(Calendar, InLeapYear, inLeapYear)
 TEMPORAL_TO_STRING(Calendar)
 // #sec-temporal.calendar.from
 BUILTIN(TemporalCalendarFrom) {
diff --git a/src/objects/js-temporal-objects.cc b/src/objects/js-temporal-objects.cc
index b0ec56c0b6..f1511cc2b5 100644
--- a/src/objects/js-temporal-objects.cc
+++ b/src/objects/js-temporal-objects.cc
@@ -4991,6 +4991,42 @@ MaybeHandle<Smi> JSTemporalCalendar::MonthsInYear(
   return handle(Smi::FromInt(months_in_year), isolate);
 }
 
+// #sec-temporal.calendar.prototype.inleapyear
+MaybeHandle<Oddball> JSTemporalCalendar::InLeapYear(
+    Isolate* isolate, Handle<JSTemporalCalendar> calendar,
+    Handle<Object> temporal_date_like) {
+  // 1. Let calendar be the this value.
+  // 2. Perform ? RequireInternalSlot(calendar,
+  // [[InitializedTemporalCalendar]]).
+  // 3. Assert: calendar.[[Identifier]] is "iso8601".
+  // 4. If Type(temporalDateLike) is not Object or temporalDateLike does not
+  // have an [[InitializedTemporalDate]], [[InitializedTemporalDateTime]], or
+  // [[InitializedTemporalYearMonth]] internal slot, then
+  if (!IsPlainDatePlainDateTimeOrPlainYearMonth(temporal_date_like)) {
+    // a. Set temporalDateLike to ? ToTemporalDate(temporalDateLike).
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, temporal_date_like,
+        ToTemporalDate(isolate, temporal_date_like,
+                       isolate->factory()->NewJSObjectWithNullProto(),
+                       "Temporal.Calendar.prototype.inLeapYear"),
+        Oddball);
+  }
+
+  // a. Let inLeapYear be ! IsISOLeapYear(temporalDateLike.[[ISOYear]]).
+  int32_t year;
+  if (temporal_date_like->IsJSTemporalPlainDate()) {
+    year = Handle<JSTemporalPlainDate>::cast(temporal_date_like)->iso_year();
+  } else if (temporal_date_like->IsJSTemporalPlainDateTime()) {
+    year =
+        Handle<JSTemporalPlainDateTime>::cast(temporal_date_like)->iso_year();
+  } else {
+    DCHECK(temporal_date_like->IsJSTemporalPlainYearMonth());
+    year =
+        Handle<JSTemporalPlainYearMonth>::cast(temporal_date_like)->iso_year();
+  }
+  return isolate->factory()->ToBoolean(IsISOLeapYear(isolate, year));
+}
+
 // #sec-temporal.calendar.prototype.tostring
 MaybeHandle<String> JSTemporalCalendar::ToString(
     Isolate* isolate, Handle<JSTemporalCalendar> calendar,
diff --git a/src/objects/js-temporal-objects.h b/src/objects/js-temporal-objects.h
index c1eefa71c1..fdc195ffe5 100644
--- a/src/objects/js-temporal-objects.h
+++ b/src/objects/js-temporal-objects.h
@@ -77,6 +77,11 @@ class JSTemporalCalendar
       Isolate* isolate, Handle<JSTemporalCalendar> calendar,
       Handle<Object> temporal_date_like);
 
+  // #sec-temporal.calendar.prototype.inleapyear
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Oddball> InLeapYear(
+      Isolate* isolate, Handle<JSTemporalCalendar> calendar,
+      Handle<Object> temporal_date_like);
+
   // #sec-temporal.calendar.prototype.tostring
   static MaybeHandle<String> ToString(Isolate* isolate,
                                       Handle<JSTemporalCalendar> calendar,
diff --git a/test/mjsunit/mjsunit.status b/test/mjsunit/mjsunit.status
index 3779eb4f56..c9aa1644e1 100644
--- a/test/mjsunit/mjsunit.status
+++ b/test/mjsunit/mjsunit.status
@@ -51,7 +51,6 @@
   'temporal/calendar-days-in-month': [FAIL],
   'temporal/calendar-days-in-week': [FAIL],
   'temporal/calendar-fields': [FAIL],
-  'temporal/calendar-in-leap-year': [FAIL],
   'temporal/calendar-merge-fields': [FAIL],
   'temporal/calendar-month': [FAIL],
   'temporal/calendar-month-code': [FAIL],
diff --git a/test/test262/test262.status b/test/test262/test262.status
index 2e1b1f019b..68c07e3a45 100644
--- a/test/test262/test262.status
+++ b/test/test262/test262.status
@@ -538,13 +538,7 @@
   'built-ins/Temporal/Calendar/prototype/fields/non-string-element-throws': [FAIL],
   'built-ins/Temporal/Calendar/prototype/fields/repeated-throw': [FAIL],
   'built-ins/Temporal/Calendar/prototype/fields/reverse': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/argument-string-with-utc-designator': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-non-integer': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-out-of-range': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-wrong-type': [FAIL],
   'built-ins/Temporal/Calendar/prototype/inLeapYear/basic': [FAIL],
-  'built-ins/Temporal/Calendar/prototype/inLeapYear/branding': [FAIL],
   'built-ins/Temporal/Calendar/prototype/inLeapYear/calendar-fields-iterable': [FAIL],
   'built-ins/Temporal/Calendar/prototype/inLeapYear/calendar-temporal-object': [FAIL],
   'built-ins/Temporal/Calendar/prototype/inLeapYear/infinity-throws-rangeerror': [FAIL],