diff --git a/packages/ui/src/components/calendar/WeekCalendar.svelte b/packages/ui/src/components/calendar/WeekCalendar.svelte
index fad05611f5..ee076ac65e 100644
--- a/packages/ui/src/components/calendar/WeekCalendar.svelte
+++ b/packages/ui/src/components/calendar/WeekCalendar.svelte
@@ -33,6 +33,11 @@
   $: weekMonday = startFromWeekStart
     ? getMonday(currentDate, mondayStart)
     : new Date(new Date(currentDate).setHours(0, 0, 0, 0))
+
+  function getDate (startDate: Date, dayIndex: number, minutes: number): Date {
+    const date = getDay(startDate, dayIndex)
+    return new Date(date.setMinutes(date.getMinutes() + minutes))
+  }
 </script>
 
 <Scroller fade={{ multipler: { top: 3, bottom: 0 } }}>
@@ -70,7 +75,7 @@
           {#each [...Array(displayedDaysCount).keys()] as dayIndex}
             <td class="calendar-td cell" style:height={cellHeight}>
               {#if $$slots.cell}
-                <slot name="cell" date={getDay(weekMonday, dayIndex, hourOfDay * 60)} />
+                <slot name="cell" date={getDate(weekMonday, dayIndex, hourOfDay * 60)} />
               {/if}
             </td>
           {/each}
diff --git a/packages/ui/src/components/calendar/internal/DateUtils.ts b/packages/ui/src/components/calendar/internal/DateUtils.ts
index 07cb441883..0dfa4662c8 100644
--- a/packages/ui/src/components/calendar/internal/DateUtils.ts
+++ b/packages/ui/src/components/calendar/internal/DateUtils.ts
@@ -48,8 +48,8 @@ export function getWeekDayName (weekDay: Date, weekFormat: 'narrow' | 'short' |
   }).format(weekDay)
 }
 
-export function day (firstDay: Date, offset: number, minutes?: number): Date {
-  return new Date(firstDay.getTime() + offset * MILLISECONDS_IN_DAY + (minutes ?? 0) * MILLISECONDS_IN_MINUTE)
+export function day (firstDay: Date, offset: number): Date {
+  return new Date(new Date(firstDay).setDate(firstDay.getDate() + offset))
 }
 
 export function weekday (firstDay: Date, w: number, d: number): Date {