diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp
index de7a9df375..3d281e125b 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp
@@ -1063,8 +1063,8 @@ ThrowCompletionOr<MoveRelativeDateResult> move_relative_date(GlobalObject& globa
     // 1. Let newDate be ? CalendarDateAdd(calendar, relativeTo, duration, options).
     auto* new_date = TRY(calendar_date_add(global_object, calendar, &relative_to, duration));
 
-    // 2. Let days be ! DaysUntil(relativeTo, newDate).
-    auto days = days_until(global_object, relative_to, *new_date);
+    // 2. Let days be DaysUntil(relativeTo, newDate).
+    auto days = days_until(relative_to, *new_date);
 
     // 3. Return the Record { [[RelativeTo]]: newDate, [[Days]]: days }.
     return MoveRelativeDateResult { .relative_to = make_handle(new_date), .days = days };
@@ -1190,8 +1190,8 @@ ThrowCompletionOr<RoundedDuration> round_duration(GlobalObject& global_object, d
         // e. Let yearsMonthsWeeksLater be ? CalendarDateAdd(calendar, relativeTo, yearsMonthsWeeks, undefined, dateAdd).
         auto* years_months_weeks_later = TRY(calendar_date_add(global_object, *calendar, relative_to, *years_months_weeks, nullptr, date_add));
 
-        // f. Let monthsWeeksInDays be ? DaysUntil(yearsLater, yearsMonthsWeeksLater).
-        auto months_weeks_in_days = days_until(global_object, *years_later, *years_months_weeks_later);
+        // f. Let monthsWeeksInDays be DaysUntil(yearsLater, yearsMonthsWeeksLater).
+        auto months_weeks_in_days = days_until(*years_later, *years_months_weeks_later);
 
         // g. Set relativeTo to yearsLater.
         relative_to = years_later;
@@ -1229,8 +1229,8 @@ ThrowCompletionOr<RoundedDuration> round_duration(GlobalObject& global_object, d
         // r. Set relativeTo to ? CalendarDateAdd(calendar, relativeTo, yearsDuration, undefined, dateAdd).
         relative_to = TRY(calendar_date_add(global_object, *calendar, relative_to, *years_duration, nullptr, date_add));
 
-        // s. Let daysPassed be ? DaysUntil(oldRelativeTo, relativeTo).
-        auto days_passed = days_until(global_object, *old_relative_to, *relative_to);
+        // s. Let daysPassed be DaysUntil(oldRelativeTo, relativeTo).
+        auto days_passed = days_until(*old_relative_to, *relative_to);
 
         // t. Set days to days - daysPassed.
         days -= days_passed;
@@ -1280,8 +1280,8 @@ ThrowCompletionOr<RoundedDuration> round_duration(GlobalObject& global_object, d
         // e. Let yearsMonthsWeeksLater be ? CalendarDateAdd(calendar, relativeTo, yearsMonthsWeeks, undefined, dateAdd).
         auto* years_months_weeks_later = TRY(calendar_date_add(global_object, *calendar, relative_to, *years_months_weeks, nullptr, date_add));
 
-        // f. Let weeksInDays be ? DaysUntil(yearsMonthsLater, yearsMonthsWeeksLater).
-        auto weeks_in_days = days_until(global_object, *years_months_later, *years_months_weeks_later);
+        // f. Let weeksInDays be DaysUntil(yearsMonthsLater, yearsMonthsWeeksLater).
+        auto weeks_in_days = days_until(*years_months_later, *years_months_weeks_later);
 
         // g. Set relativeTo to yearsMonthsLater.
         relative_to = years_months_later;
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/Duration.h b/Userland/Libraries/LibJS/Runtime/Temporal/Duration.h
index c9934ce127..b407d37cb1 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/Duration.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/Duration.h
@@ -9,6 +9,7 @@
 #include <AK/Optional.h>
 #include <LibJS/Heap/Handle.h>
 #include <LibJS/Runtime/Completion.h>
+#include <LibJS/Runtime/Date.h>
 #include <LibJS/Runtime/Object.h>
 #include <LibJS/Runtime/Temporal/PlainDate.h>
 #include <LibJS/Runtime/Temporal/PlainDateTime.h>
@@ -163,13 +164,22 @@ ThrowCompletionOr<Duration*> add_duration_to_or_subtract_duration_from_duration(
 
 // 7.5.22 DaysUntil ( earlier, later ), https://tc39.es/proposal-temporal/#sec-temporal-daysuntil
 template<typename EarlierObjectType, typename LaterObjectType>
-double days_until(GlobalObject& global_object, EarlierObjectType& earlier, LaterObjectType& later)
+double days_until(EarlierObjectType& earlier, LaterObjectType& later)
 {
-    // 1. Let difference be ! DifferenceISODate(earlier.[[ISOYear]], earlier.[[ISOMonth]], earlier.[[ISODay]], later.[[ISOYear]], later.[[ISOMonth]], later.[[ISODay]], "day").
-    auto difference = difference_iso_date(global_object, earlier.iso_year(), earlier.iso_month(), earlier.iso_day(), later.iso_year(), later.iso_month(), later.iso_day(), "day"sv);
+    // 1. Let epochDays1 be MakeDay(𝔽(earlier.[[ISOYear]]), 𝔽(earlier.[[ISOMonth]] - 1), 𝔽(earlier.[[ISODay]])).
+    auto epoch_days_1 = make_day(earlier.iso_year(), earlier.iso_month() - 1, earlier.iso_day());
 
-    // 2. Return difference.[[Days]].
-    return difference.days;
+    // 2. Assert: epochDays1 is finite.
+    VERIFY(isfinite(epoch_days_1));
+
+    // 3. Let epochDays2 be MakeDay(𝔽(later.[[ISOYear]]), 𝔽(later.[[ISOMonth]] - 1), 𝔽(later.[[ISODay]])).
+    auto epoch_days_2 = make_day(later.iso_year(), later.iso_month() - 1, later.iso_day());
+
+    // 4. Assert: epochDays2 is finite.
+    VERIFY(isfinite(epoch_days_2));
+
+    // 5. Return ℝ(epochDays2) - ℝ(epochDays1).
+    return epoch_days_2 - epoch_days_1;
 }
 
 }