diff --git a/src/views/vacation/VacationManagement.vue b/src/views/vacation/VacationManagement.vue
index 52dbbe3..43693a8 100644
--- a/src/views/vacation/VacationManagement.vue
+++ b/src/views/vacation/VacationManagement.vue
@@ -143,6 +143,12 @@ const calendarOptions = reactive({
     dateClick: handleDateClick,
     datesSet: handleMonthChange,
     events: calendarEvents,
+    customButtons: {
+        today: {
+            text: 'TODAY',
+            click: () => fullCalendarRef.value?.getApi().today(),
+        },
+    },
 });
 // 캘린더 월 변경
 function handleMonthChange(viewInfo) {
@@ -178,6 +184,21 @@ function handleDateClick(info) {
 
     const isMyVacation = myVacations.value.some(vac => vac.date.substring(0, 10) === clickedDateStr && !vac.receiverId);
 
+    if (!selectedDates.value.has(clickedDateStr) && isMyVacation && halfDayType.value) {
+        const existingVacation = myVacations.value.find(vac => vac.date.substring(0, 10) === clickedDateStr && !vac.receiverId);
+        const selectedType =
+            halfDayType.value === "AM" ? "700101" :
+            halfDayType.value === "PM" ? "700102" : "700103";
+        if (existingVacation.type === selectedType) {
+            toastStore.onToast("이미 사용한 연차입니다.", "e");
+            if (halfDayButtonsRef.value) {
+                halfDayButtonsRef.value.resetHalfDay();
+            }
+            halfDayType.value = null;
+            return;
+        }
+    }
+
     // 이미 활성화된 날짜를 한 번 더 클릭하면 비활성화
     if (currentValue && currentValue !== "delete") {
         selectedDates.value.delete(clickedDateStr);