diff --git a/src/main/kotlin/roomescape/reservation/implement/ReservationValidator.kt b/src/main/kotlin/roomescape/reservation/implement/ReservationValidator.kt
index a7f0ba3e..257c9815 100644
--- a/src/main/kotlin/roomescape/reservation/implement/ReservationValidator.kt
+++ b/src/main/kotlin/roomescape/reservation/implement/ReservationValidator.kt
@@ -22,25 +22,26 @@ private val log: KLogger = KotlinLogging.logger {}
 class ReservationValidator(
     private val reservationRepository: ReservationRepository,
 ) {
-    fun validateIsNotPast(
+    fun validateIsPast(
         requestDate: LocalDate,
         requestTime: LocalTime,
     ) {
         val now = LocalDateTime.now()
         val requestDateTime = LocalDateTime.of(requestDate, requestTime)
-        log.debug { "[ReservationValidator.validateDateAndTime] 시작. request=$requestDateTime, now=$now" }
+        log.debug { "[ReservationValidator.validateIsPast] 시작. request=$requestDateTime, now=$now" }
 
         if (requestDateTime.isBefore(now)) {
-            log.info { "[ReservationValidator.validateDateAndTime] 날짜 범위 오류. request=$requestDateTime, now=$now" }
+            log.info { "[ReservationValidator.validateIsPast] 날짜 범위 오류. request=$requestDateTime, now=$now" }
             throw ReservationException(ReservationErrorCode.PAST_REQUEST_DATETIME)
         }
 
-        log.debug { "[ReservationValidator.validateDateAndTime] 완료. request=$requestDateTime, now=$now" }
+        log.debug { "[ReservationValidator.validateIsPast] 완료. request=$requestDateTime, now=$now" }
     }
 
     fun validateSearchDateRange(startFrom: LocalDate?, endAt: LocalDate?) {
         log.debug { "[ReservationValidator.validateSearchDateRange] 시작: startFrom=$startFrom, endAt=$endAt" }
         if (startFrom == null || endAt == null) {
+            log.debug { "[ReservationValidator.validateSearchDateRange] 완료: startFrom=$startFrom, endAt=$endAt" }
             return
         }
         if (startFrom.isAfter(endAt)) {
@@ -129,4 +130,15 @@ class ReservationValidator(
 
         log.debug { "[ReservationValidator.validateDeleteAuthority] 완료: reservationId=${reservation.id}, requesterId=$requesterId" }
     }
+
+    fun validateAlreadyConfirmed(reservationId: Long) {
+        log.debug { "[ReservationValidator.validateAlreadyConfirmed] 시작: reservationId=$reservationId" }
+
+        if (reservationRepository.isExistConfirmedReservation(reservationId)) {
+            log.warn { "[ReservationWriter.confirm] 이미 확정된 예약: reservationId=$reservationId" }
+            throw ReservationException(ReservationErrorCode.CONFIRMED_RESERVATION_ALREADY_EXISTS)
+        }
+
+        log.debug { "[ReservationValidator.validateAlreadyConfirmed] 완료: reservationId=$reservationId" }
+    }
 }
diff --git a/src/main/kotlin/roomescape/reservation/implement/ReservationWriter.kt b/src/main/kotlin/roomescape/reservation/implement/ReservationWriter.kt
index d2a7b7dd..23f34de8 100644
--- a/src/main/kotlin/roomescape/reservation/implement/ReservationWriter.kt
+++ b/src/main/kotlin/roomescape/reservation/implement/ReservationWriter.kt
@@ -39,7 +39,7 @@ class ReservationWriter(
                     "date=${date}, timeId=${timeId}, themeId=${themeId}, memberId=${memberId}, status=${status}"
         }
         val time = timeFinder.findById(timeId).also {
-            reservationValidator.validateIsNotPast(date, it.startAt)
+            reservationValidator.validateIsPast(date, it.startAt)
         }
         val theme = themeFinder.findById(themeId)
 
@@ -95,14 +95,9 @@ class ReservationWriter(
     fun confirm(reservationId: Long) {
         log.debug { "[ReservationWriter.confirm] 대기 여부 확인 시작: reservationId=$reservationId" }
 
-        if (reservationRepository.isExistConfirmedReservation(reservationId)) {
-            log.warn { "[ReservationWriter.confirm] 이미 확정된 예약 존재: reservationId=$reservationId" }
-            throw ReservationException(ReservationErrorCode.CONFIRMED_RESERVATION_ALREADY_EXISTS)
-        }
+        reservationValidator.validateAlreadyConfirmed(reservationId)
 
-        reservationRepository.updateStatusByReservationId(
-            reservationId, ReservationStatus.CONFIRMED_PAYMENT_REQUIRED
-        )
+        reservationRepository.updateStatusByReservationId(reservationId, ReservationStatus.CONFIRMED_PAYMENT_REQUIRED)
 
         log.debug { "[ReservationWriter.confirm] 완료: reservationId=$reservationId, status=${ReservationStatus.CONFIRMED_PAYMENT_REQUIRED}" }
     }
diff --git a/src/test/kotlin/roomescape/time/implement/TimeFinderTest.kt b/src/test/kotlin/roomescape/time/implement/TimeFinderTest.kt
index e8d4c9f7..66520c80 100644
--- a/src/test/kotlin/roomescape/time/implement/TimeFinderTest.kt
+++ b/src/test/kotlin/roomescape/time/implement/TimeFinderTest.kt
@@ -34,7 +34,7 @@ class TimeFinderTest : FunSpec({
                 timeRepository.findAll()
             } returns listOf(mockk(), mockk(), mockk())
 
-            timeRepository.findAll() shouldHaveSize 3
+            timeFinder.findAll() shouldHaveSize 3
         }
     }