diff --git a/src/main/kotlin/com/didit/adapter/integration/scheduler/MissionScheduler.kt b/src/main/kotlin/com/didit/adapter/integration/scheduler/MissionScheduler.kt
index 13506a9a..5f78223b 100644
--- a/src/main/kotlin/com/didit/adapter/integration/scheduler/MissionScheduler.kt
+++ b/src/main/kotlin/com/didit/adapter/integration/scheduler/MissionScheduler.kt
@@ -3,13 +3,11 @@ package com.didit.adapter.integration.scheduler
 import com.didit.application.achievement.required.MissionRepository
 import com.didit.application.achievement.required.UserMissionRepository
 import com.didit.application.retrospect.required.RetrospectiveRepository
+import com.didit.domain.shared.ServiceTime
 import jakarta.transaction.Transactional
 import org.slf4j.LoggerFactory
 import org.springframework.scheduling.annotation.Scheduled
 import org.springframework.stereotype.Component
-import java.time.LocalDate
-import java.time.LocalDateTime
-import java.time.LocalTime
 import java.time.temporal.TemporalAdjusters
 
 @Component
@@ -42,14 +40,13 @@ class MissionScheduler(
 
         consecutiveWeekMissions.forEach { userMission ->
             val lastWeekStart =
-                LocalDate.now().with(TemporalAdjusters.previousOrSame(java.time.DayOfWeek.MONDAY)).minusWeeks(1)
-            val lastWeekEnd = lastWeekStart.plusDays(6)
+                ServiceTime.today().with(TemporalAdjusters.previousOrSame(java.time.DayOfWeek.MONDAY)).minusWeeks(1)
 
             val lastWeekRetroCount =
                 retrospectiveRepository.countCompletedByUserIdAndPeriod(
                     userId = userMission.userId,
-                    from = LocalDateTime.of(lastWeekStart, LocalTime.MIDNIGHT),
-                    to = LocalDateTime.of(lastWeekEnd, LocalTime.of(23, 59, 59)),
+                    from = ServiceTime.startOfDayUtc(lastWeekStart),
+                    to = ServiceTime.startOfDayUtc(lastWeekStart.plusWeeks(1)),
                 )
 
             if (lastWeekRetroCount == 0) {
diff --git a/src/main/kotlin/com/didit/application/achievement/MissionQueryService.kt b/src/main/kotlin/com/didit/application/achievement/MissionQueryService.kt
index 33cda84d..f7189df2 100644
--- a/src/main/kotlin/com/didit/application/achievement/MissionQueryService.kt
+++ b/src/main/kotlin/com/didit/application/achievement/MissionQueryService.kt
@@ -16,12 +16,11 @@ import com.didit.domain.achievement.Mission
 import com.didit.domain.achievement.MissionStatus
 import com.didit.domain.achievement.MissionType
 import com.didit.domain.achievement.UserMission
+import com.didit.domain.shared.ServiceTime
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
 import java.time.DayOfWeek
 import java.time.LocalDate
-import java.time.LocalDateTime
-import java.time.LocalTime
 import java.time.temporal.TemporalAdjusters
 import java.util.UUID
 
@@ -89,15 +88,14 @@ class MissionQueryService(
             return null
         }
 
-        val weekStartDate = getWeekStartDate(LocalDate.now())
-        val weekEndDate = weekStartDate.plusDays(6)
-        val from = LocalDateTime.of(weekStartDate, LocalTime.MIDNIGHT)
-        val to = LocalDateTime.of(weekEndDate, LocalTime.of(23, 59, 59))
+        val weekStartDate = getWeekStartDate(ServiceTime.today())
+        val from = ServiceTime.startOfDayUtc(weekStartDate)
+        val to = ServiceTime.startOfDayUtc(weekStartDate.plusWeeks(1))
 
         val completedRetros = retrospectiveRepository.findCompletedByUserIdAndPeriod(userId, from, to)
-        val completedDates = completedRetros.map { it.completedAt?.toLocalDate() }.toSet()
+        val completedDates = completedRetros.mapNotNull { it.completedAt?.let(ServiceTime::toServiceDate) }.toSet()
 
-        val today = LocalDate.now()
+        val today = ServiceTime.today()
         val days = mutableListOf<Boolean>()
 
         for (i in 0..6) {