diff --git a/pkg/cmd/backtest.go b/pkg/cmd/backtest.go
index ebe501722..89af3dfd4 100644
--- a/pkg/cmd/backtest.go
+++ b/pkg/cmd/backtest.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 	"syscall"
 	"time"
@@ -214,13 +215,13 @@ var BacktestCmd = &cobra.Command{
 
 		if wantSync {
 			log.Infof("starting synchronization: %v", userConfig.Backtest.Symbols)
-			if err := sync(ctx, userConfig, backtestService, sourceExchanges, syncFromTime, endTime); err != nil {
+			if err := sync(ctx, userConfig, backtestService, sourceExchanges, syncFromTime.Local(), endTime.Local()); err != nil {
 				return err
 			}
 			log.Info("synchronization done")
 
 			if shouldVerify {
-				err := verify(userConfig, backtestService, sourceExchanges, syncFromTime, endTime)
+				err := verify(userConfig, backtestService, sourceExchanges, syncFromTime.Local(), endTime.Local())
 				if err != nil {
 					return err
 				}
@@ -662,7 +663,16 @@ func sync(ctx context.Context, userConfig *bbgo.Config, backtestService *service
 				supportIntervals = types.SupportedIntervals
 			}
 
+			// sort intervals
+			var intervals []types.Interval
 			for interval := range supportIntervals {
+				intervals = append(intervals, interval)
+			}
+			sort.Slice(intervals, func(i, j int) bool {
+				return intervals[i].Duration() < intervals[j].Duration()
+			})
+
+			for _, interval := range intervals {
 				firstKLine, err := backtestService.QueryFirstKLine(sourceExchange.Name(), symbol, interval)
 				if err != nil {
 					return errors.Wrapf(err, "failed to query backtest kline")
diff --git a/pkg/exchange/batch/kline.go b/pkg/exchange/batch/kline.go
index 2e9c65981..a4053fe34 100644
--- a/pkg/exchange/batch/kline.go
+++ b/pkg/exchange/batch/kline.go
@@ -2,6 +2,7 @@ package batch
 
 import (
 	"context"
+	"strconv"
 	"time"
 
 	"github.com/c9s/bbgo/pkg/types"
@@ -22,11 +23,11 @@ func (e *KLineBatchQuery) Query(ctx context.Context, symbol string, interval typ
 			})
 		},
 		T: func(obj interface{}) time.Time {
-			return time.Time(obj.(types.KLine).StartTime).UTC()
+			return time.Time(obj.(types.KLine).StartTime)
 		},
 		ID: func(obj interface{}) string {
 			kline := obj.(types.KLine)
-			return kline.StartTime.String()
+			return strconv.FormatInt(kline.StartTime.UnixMilli(), 10)
 		},
 	}
 
diff --git a/pkg/exchange/binance/exchange.go b/pkg/exchange/binance/exchange.go
index 7c9dd96b4..ccfcdc3b9 100644
--- a/pkg/exchange/binance/exchange.go
+++ b/pkg/exchange/binance/exchange.go
@@ -1240,11 +1240,18 @@ func (e *Exchange) QueryKLines(ctx context.Context, symbol string, interval type
 
 	var kLines []types.KLine
 	for _, k := range resp {
+		startTime := types.NewTimeFromUnix(0, k.OpenTime*int64(time.Millisecond))
+		if options.EndTime != nil {
+			if !startTime.Before(*options.EndTime) {
+				continue
+			}
+		}
+
 		kLines = append(kLines, types.KLine{
 			Exchange:                 types.ExchangeBinance,
 			Symbol:                   symbol,
 			Interval:                 interval,
-			StartTime:                types.NewTimeFromUnix(0, k.OpenTime*int64(time.Millisecond)),
+			StartTime:                startTime,
 			EndTime:                  types.NewTimeFromUnix(0, k.CloseTime*int64(time.Millisecond)),
 			Open:                     fixedpoint.MustNewFromString(k.Open),
 			Close:                    fixedpoint.MustNewFromString(k.Close),
@@ -1259,6 +1266,11 @@ func (e *Exchange) QueryKLines(ctx context.Context, symbol string, interval type
 			Closed:                   true,
 		})
 	}
+
+	kLines = types.SortKLinesAscending(kLines)
+	for _, k := range kLines {
+		log.Info(k)
+	}
 	return kLines, nil
 }
 
diff --git a/pkg/service/backtest.go b/pkg/service/backtest.go
index 7859c38a3..cb9b28d51 100644
--- a/pkg/service/backtest.go
+++ b/pkg/service/backtest.go
@@ -41,20 +41,25 @@ func (s *BacktestService) SyncKLineByInterval(ctx context.Context, exchange type
 			Type:   types.KLine{},
 			Select: SelectLastKLines(exchange.Name(), symbol, interval, startTime, endTime, 100),
 			Time: func(obj interface{}) time.Time {
-				return obj.(types.KLine).StartTime.Time().UTC()
+				return obj.(types.KLine).StartTime.Time()
 			},
 			ID: func(obj interface{}) string {
 				kline := obj.(types.KLine)
-				return kline.Symbol + kline.Interval.String() + strconv.FormatInt(kline.StartTime.UnixMilli(), 10)
+				return strconv.FormatInt(kline.StartTime.UnixMilli(), 10)
+				// return kline.Symbol + kline.Interval.String() + strconv.FormatInt(kline.StartTime.UnixMilli(), 10)
 			},
 			BatchQuery: func(ctx context.Context, startTime, endTime time.Time) (interface{}, chan error) {
 				q := &batch.KLineBatchQuery{Exchange: exchange}
 				return q.Query(ctx, symbol, interval, startTime, endTime)
 			},
-			BatchInsertBuffer: 500,
-			BatchInsert: func(obj interface{}) error {
-				kLines := obj.([]types.KLine)
-				return s.BatchInsert(kLines)
+			// BatchInsertBuffer: 500,
+			// BatchInsert: func(obj interface{}) error {
+			// 	kLines := obj.([]types.KLine)
+			// 	return s.BatchInsert(kLines)
+			// },
+			Insert: func(obj interface{}) error {
+				kline := obj.(types.KLine)
+				return s.Insert(kline)
 			},
 			LogInsert: log.GetLevel() == log.DebugLevel,
 		},
@@ -331,10 +336,6 @@ func (t *TimeRange) String() string {
 // create a time range slice []TimeRange
 // iterate the []TimeRange slice to sync data.
 func (s *BacktestService) SyncPartial(ctx context.Context, ex types.Exchange, symbol string, interval types.Interval, since, until time.Time) error {
-	// truncate time point to minute
-	since = since.Truncate(time.Minute)
-	until = until.Truncate(time.Minute)
-
 	t1, t2, err := s.QueryExistingDataRange(ctx, ex, symbol, interval, since, until)
 	if err != nil && err != sql.ErrNoRows {
 		return err
@@ -345,7 +346,6 @@ func (s *BacktestService) SyncPartial(ctx context.Context, ex types.Exchange, sy
 		return s.SyncFresh(ctx, ex, symbol, interval, since, until)
 	}
 
-	log.Debugf("found existing kline data, now using partial sync...")
 	timeRanges, err := s.FindMissingTimeRanges(ctx, ex, symbol, interval, t1.Time(), t2.Time())
 	if err != nil {
 		return err
@@ -358,22 +358,22 @@ func (s *BacktestService) SyncPartial(ctx context.Context, ex types.Exchange, sy
 	// there are few cases:
 	// t1 == since && t2 == until
 	// [since] ------- [t1] data [t2] ------ [until]
-	if since.Before(t1.Time()) {
+	if since.Before(t1.Time()) && t1.Time().Sub(since) > interval.Duration() {
 		// shift slice
 		timeRanges = append([]TimeRange{
-			{Start: since.Add(-2 * time.Second), End: t1.Time()}, // include since
+			{Start: since.Add(-2 * time.Second), End: t1.Time()}, // we should include since
 		}, timeRanges...)
 	}
 
-	if t2.Time().Before(until) {
+	if t2.Time().Before(until) && until.Sub(t2.Time()) > interval.Duration() {
 		timeRanges = append(timeRanges, TimeRange{
 			Start: t2.Time(),
-			End:   until.Add(2 * time.Second), // include until
+			End:   until.Add(-interval.Duration()), // include until
 		})
 	}
 
 	for _, timeRange := range timeRanges {
-		err = s.SyncKLineByInterval(ctx, ex, symbol, interval, timeRange.Start.Add(time.Second), timeRange.End.Add(-time.Second))
+		err = s.SyncKLineByInterval(ctx, ex, symbol, interval, timeRange.Start.Add(time.Second), timeRange.End)
 		if err != nil {
 			return err
 		}
@@ -481,6 +481,9 @@ func SelectKLineTimeRange(ex types.ExchangeName, symbol string, interval types.I
 	}
 
 	if len(args) == 2 {
+		// NOTE
+		// sqlite does not support timezone format, so we are converting to local timezone
+		// mysql works in this case, so this is a workaround
 		since := args[0]
 		until := args[1]
 		conditions = append(conditions, sq.Expr("`start_time` BETWEEN ? AND ?", since, until))
diff --git a/pkg/service/sync_task.go b/pkg/service/sync_task.go
index a04239591..796bccfe9 100644
--- a/pkg/service/sync_task.go
+++ b/pkg/service/sync_task.go
@@ -92,8 +92,9 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 
 	defer func() {
 		if sel.BatchInsert != nil && batchBufferRefVal.Len() > 0 {
-			if err := sel.BatchInsert(batchBufferRefVal.Interface()); err != nil {
-				logrus.WithError(err).Errorf("batch insert error")
+			slice := batchBufferRefVal.Interface()
+			if err := sel.BatchInsert(slice); err != nil {
+				logrus.WithError(err).Errorf("batch insert error: %+v", slice)
 			}
 		}
 	}()
@@ -107,7 +108,6 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 		default:
 			v, ok := dataCRef.Recv()
 			if !ok {
-
 				err := <-errC
 				return err
 			}
@@ -118,6 +118,11 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 				continue
 			}
 
+			tt := sel.Time(obj)
+			if tt.Before(startTime) || tt.Equal(endTime) || tt.After(endTime) {
+				continue
+			}
+
 			if sel.Filter != nil {
 				if !sel.Filter(obj) {
 					continue
@@ -125,7 +130,7 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 			}
 
 			if sel.BatchInsert != nil {
-				if batchBufferRefVal.Len() >= sel.BatchInsertBuffer {
+				if batchBufferRefVal.Len() >= sel.BatchInsertBuffer-1 {
 					if sel.LogInsert {
 						logrus.Infof("batch inserting %d %T", batchBufferRefVal.Len(), obj)
 					} else {
@@ -148,10 +153,12 @@ func (sel SyncTask) execute(ctx context.Context, db *sqlx.DB, startTime time.Tim
 				if sel.Insert != nil {
 					// for custom insert
 					if err := sel.Insert(obj); err != nil {
+						logrus.WithError(err).Errorf("can not insert record: %v", obj)
 						return err
 					}
 				} else {
 					if err := insertType(db, obj); err != nil {
+						logrus.WithError(err).Errorf("can not insert record: %v", obj)
 						return err
 					}
 				}