diff --git a/backend/plugins/zentao/tasks/bug_convertor.go b/backend/plugins/zentao/tasks/bug_convertor.go
index 5c926cee63b..6a0f679b8a5 100644
--- a/backend/plugins/zentao/tasks/bug_convertor.go
+++ b/backend/plugins/zentao/tasks/bug_convertor.go
@@ -105,8 +105,10 @@ func ConvertBug(taskCtx plugin.SubTaskContext) errors.Error {
 			if toolEntity.AssignedToId != 0 {
 				domainEntity.AssigneeId = accountIdGen.Generate(data.Options.ConnectionId, toolEntity.AssignedToId)
 			}
-			if toolEntity.ClosedDate != nil {
-				temp := uint(toolEntity.ClosedDate.ToNullableTime().Sub(toolEntity.OpenedDate.ToTime()).Minutes())
+			closedDate := toolEntity.ClosedDate
+			openedDate := toolEntity.OpenedDate
+			if closedDate != nil && closedDate.ToTime().After(openedDate.ToTime()) {
+				temp := uint(closedDate.ToNullableTime().Sub(openedDate.ToTime()).Minutes())
 				domainEntity.LeadTimeMinutes = &temp
 			}
 			var results []interface{}
diff --git a/backend/plugins/zentao/tasks/story_convertor.go b/backend/plugins/zentao/tasks/story_convertor.go
index f9aea6aaafe..c8b072766eb 100644
--- a/backend/plugins/zentao/tasks/story_convertor.go
+++ b/backend/plugins/zentao/tasks/story_convertor.go
@@ -117,8 +117,10 @@ func ConvertStory(taskCtx plugin.SubTaskContext) errors.Error {
 				results = append(results, issueAssignee)
 			}
 
-			if toolEntity.ClosedDate != nil {
-				temp := uint(toolEntity.ClosedDate.ToNullableTime().Sub(toolEntity.OpenedDate.ToTime()).Minutes())
+			closedDate := toolEntity.ClosedDate
+			openedDate := toolEntity.OpenedDate
+			if closedDate != nil && closedDate.ToTime().After(openedDate.ToTime()) {
+				temp := uint(closedDate.ToNullableTime().Sub(openedDate.ToTime()).Minutes())
 				domainEntity.LeadTimeMinutes = &temp
 			}
 
diff --git a/backend/plugins/zentao/tasks/task_convertor.go b/backend/plugins/zentao/tasks/task_convertor.go
index 3489b6c29fe..43d8b94c280 100644
--- a/backend/plugins/zentao/tasks/task_convertor.go
+++ b/backend/plugins/zentao/tasks/task_convertor.go
@@ -108,8 +108,10 @@ func ConvertTask(taskCtx plugin.SubTaskContext) errors.Error {
 			if toolEntity.AssignedToId != 0 {
 				domainEntity.AssigneeId = accountIdGen.Generate(data.Options.ConnectionId, toolEntity.AssignedToId)
 			}
-			if toolEntity.ClosedDate != nil {
-				temp := uint(toolEntity.ClosedDate.ToNullableTime().Sub(toolEntity.OpenedDate.ToTime()).Minutes())
+			closedDate := toolEntity.ClosedDate
+			openedDate := toolEntity.OpenedDate
+			if closedDate != nil && closedDate.ToTime().After(openedDate.ToTime()) {
+				temp := uint(closedDate.ToNullableTime().Sub(openedDate.ToTime()).Minutes())
 				domainEntity.LeadTimeMinutes = &temp
 			}
 			var results []interface{}