diff --git a/backend/src/main/java/net/beetechgroup/beetask/usecase/dashboard/DashboardUseCase.java b/backend/src/main/java/net/beetechgroup/beetask/usecase/dashboard/DashboardUseCase.java
index eddb09b..a253d93 100644
--- a/backend/src/main/java/net/beetechgroup/beetask/usecase/dashboard/DashboardUseCase.java
+++ b/backend/src/main/java/net/beetechgroup/beetask/usecase/dashboard/DashboardUseCase.java
@@ -130,7 +130,8 @@ public class DashboardUseCase {
 
     private long calculateMinutesInRange(TaskHistoryItem item, LocalDateTime start, LocalDateTime end) {
         LocalDateTime effectiveStart = item.getStartAt().isBefore(start) ? start : item.getStartAt();
-        LocalDateTime effectiveEnd = Objects.isNull(item.getEndAt()) || item.getEndAt().isAfter(end) ? end : item.getEndAt();
+        LocalDateTime itemEnd = Objects.nonNull(item.getEndAt()) ? item.getEndAt() : LocalDateTime.now();
+        LocalDateTime effectiveEnd = itemEnd.isAfter(end) ? end : itemEnd;
 
         if (effectiveStart.isAfter(effectiveEnd)) return 0;
 
diff --git a/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/OrgDashboardUseCase.java b/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/OrgDashboardUseCase.java
index c73bc94..de6e3b9 100644
--- a/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/OrgDashboardUseCase.java
+++ b/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/OrgDashboardUseCase.java
@@ -140,7 +140,8 @@ public class OrgDashboardUseCase {
 
     private long calculateMinutesInRange(TaskHistoryItem item, LocalDateTime start, LocalDateTime end) {
         LocalDateTime effectiveStart = item.getStartAt().isBefore(start) ? start : item.getStartAt();
-        LocalDateTime effectiveEnd = Objects.isNull(item.getEndAt()) || item.getEndAt().isAfter(end) ? end : item.getEndAt();
+        LocalDateTime itemEnd = Objects.nonNull(item.getEndAt()) ? item.getEndAt() : LocalDateTime.now();
+        LocalDateTime effectiveEnd = itemEnd.isAfter(end) ? end : itemEnd;
         if (effectiveStart.isAfter(effectiveEnd)) return 0;
         return Duration.between(effectiveStart, effectiveEnd).toMinutes();
     }
diff --git a/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/memberdetail/MemberDetailUseCase.java b/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/memberdetail/MemberDetailUseCase.java
index e8637a5..6c91ba6 100644
--- a/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/memberdetail/MemberDetailUseCase.java
+++ b/backend/src/main/java/net/beetechgroup/beetask/usecase/orgdashboard/memberdetail/MemberDetailUseCase.java
@@ -66,7 +66,8 @@ public class MemberDetailUseCase {
             for (TaskHistoryItem h : task.getHistory()) {
                 if (!isWithinPeriod(h, start, end)) continue;
                 LocalDateTime effectiveStart = h.getStartAt().isBefore(start) ? start : h.getStartAt();
-                LocalDateTime effectiveEnd = (Objects.isNull(h.getEndAt()) || h.getEndAt().isAfter(end)) ? end : h.getEndAt();
+                LocalDateTime itemEnd = Objects.nonNull(h.getEndAt()) ? h.getEndAt() : LocalDateTime.now();
+                LocalDateTime effectiveEnd = itemEnd.isAfter(end) ? end : itemEnd;
                 if (effectiveStart.isAfter(effectiveEnd)) continue;
 
                 long minutes = Duration.between(effectiveStart, effectiveEnd).toMinutes();