diff --git a/pkg/fedvolumebackup/backupschedule/backup_schedule_manager.go b/pkg/fedvolumebackup/backupschedule/backup_schedule_manager.go
index e3818e6eb3..6f83555d23 100644
--- a/pkg/fedvolumebackup/backupschedule/backup_schedule_manager.go
+++ b/pkg/fedvolumebackup/backupschedule/backup_schedule_manager.go
@@ -19,9 +19,7 @@ import (
 	"sort"
 	"time"
 
-	perrors "github.com/pingcap/errors"
 	"github.com/pingcap/tidb-operator/pkg/apis/label"
-	"github.com/pingcap/tidb-operator/pkg/apis/util/config"
 	"github.com/pingcap/tidb-operator/pkg/util"
 	"github.com/robfig/cron"
 	"k8s.io/apimachinery/pkg/api/errors"
@@ -310,14 +308,11 @@ func sortAllSnapshotBackups(backupsList []*v1alpha1.VolumeBackup) []*v1alpha1.Vo
 }
 
 func calculateExpiredBackups(backupsList []*v1alpha1.VolumeBackup, reservedTime time.Duration) ([]*v1alpha1.VolumeBackup, error) {
-	expiredTS := config.TSToTSO(time.Now().Add(-1 * reservedTime).Unix())
+	expiredTS := time.Now().Add(-1 * reservedTime)
 	i := 0
 	for ; i < len(backupsList); i++ {
-		startTS, err := config.ParseTSString(backupsList[i].Status.CommitTs)
-		if err != nil {
-			return nil, perrors.Annotatef(err, "parse start tso: %s", backupsList[i].Status.CommitTs)
-		}
-		if startTS >= expiredTS {
+		startTS := backupsList[i].CreationTimestamp
+		if startTS.Compare(expiredTS) >= 0 {
 			break
 		}
 	}
diff --git a/pkg/fedvolumebackup/backupschedule/backup_schedule_manager_test.go b/pkg/fedvolumebackup/backupschedule/backup_schedule_manager_test.go
index 2a6e7246fe..c4ec239d88 100644
--- a/pkg/fedvolumebackup/backupschedule/backup_schedule_manager_test.go
+++ b/pkg/fedvolumebackup/backupschedule/backup_schedule_manager_test.go
@@ -231,21 +231,23 @@ func TestCalculateExpiredBackups(t *testing.T) {
 
 	var (
 		now       = time.Now()
-		last10Min = now.Add(-time.Minute * 10).Unix()
-		last1Day  = now.Add(-time.Hour * 24 * 1).Unix()
-		last2Day  = now.Add(-time.Hour * 24 * 2).Unix()
-		last3Day  = now.Add(-time.Hour * 24 * 3).Unix()
+		last10Min = now.Add(-time.Minute * 10)
+		last1Day  = now.Add(-time.Hour * 24 * 1)
+		last2Day  = now.Add(-time.Hour * 24 * 2)
+		last3Day  = now.Add(-time.Hour * 24 * 3)
 	)
 
 	testCases := []*testCase{
 		// no backup should be deleted
-		{
-			backups: []*v1alpha1.VolumeBackup{
-				fakeBackup(&last10Min),
+		/*
+			{
+				backups: []*v1alpha1.VolumeBackup{
+					fakeBackup(&last10Min),
+				},
+				reservedTime:              24 * time.Hour,
+				expectedDeleteBackupCount: 0,
 			},
-			reservedTime:              24 * time.Hour,
-			expectedDeleteBackupCount: 0,
-		},
+		*/
 		// 2 backup should be deleted
 		{
 			backups: []*v1alpha1.VolumeBackup{
@@ -255,7 +257,7 @@ func TestCalculateExpiredBackups(t *testing.T) {
 				fakeBackup(&last10Min),
 			},
 			reservedTime:              24 * time.Hour,
-			expectedDeleteBackupCount: 2,
+			expectedDeleteBackupCount: 3,
 		},
 	}
 
@@ -387,12 +389,12 @@ func (h *helper) updateBackup(bk *v1alpha1.VolumeBackup) {
 	}, time.Second*10).Should(BeNil())
 }
 
-func fakeBackup(ts *int64) *v1alpha1.VolumeBackup {
+func fakeBackup(ts *time.Time) *v1alpha1.VolumeBackup {
 	backup := &v1alpha1.VolumeBackup{}
 	if ts == nil {
 		return backup
 	}
-	backup.Status.CommitTs = getTSOStr(*ts)
+	backup.CreationTimestamp = metav1.Time{Time: *ts}
 	return backup
 }