diff --git a/model/rule.go b/model/rule.go
index d6a82f1..25bcfd6 100644
--- a/model/rule.go
+++ b/model/rule.go
@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"gorm.io/gorm"
+	"github.com/gorhill/cronexpr"
 )
 
 const (
@@ -24,7 +25,7 @@ type Rule struct {
 	Min           float64         `json:"min,omitempty"`            // 最小阈值 (百分比、字节 kb ÷ 1024)
 	Max           float64         `json:"max,omitempty"`            // 最大阈值 (百分比、字节 kb ÷ 1024)
 	CycleStart    time.Time       `json:"cycle_start,omitempty"`    // 流量统计的开始时间
-	CycleInterval uint64          `json:"cycle_interval,omitempty"` // 流量统计周期
+	CycleInterval string          `json:"cycle_interval,omitempty"` // crontab 表达式
 	Duration      uint64          `json:"duration,omitempty"`       // 持续时间 (秒)
 	Cover         uint64          `json:"cover,omitempty"`          // 覆盖范围 RuleCoverAll/IgnoreAll
 	Ignore        map[uint64]bool `json:"ignore,omitempty"`         // 覆盖范围的排除
@@ -88,21 +89,21 @@ func (u *Rule) Snapshot(cycleTransferStats *CycleTransferStats, server *Server,
 		}
 	case "transfer_in_cycle":
 		src = float64(server.State.NetInTransfer - uint64(server.PrevHourlyTransferIn))
-		if u.CycleInterval != 1 {
+		if u.CycleInterval != nil {
 			var res NResult
 			db.Model(&Transfer{}).Select("SUM(`in`) AS n").Where("created_at > ? AND server_id = ?", u.GetTransferDurationStart(), server.ID).Scan(&res)
 			src += float64(res.N)
 		}
 	case "transfer_out_cycle":
 		src = float64(server.State.NetOutTransfer - uint64(server.PrevHourlyTransferOut))
-		if u.CycleInterval != 1 {
+		if u.CycleInterval != nil {
 			var res NResult
 			db.Model(&Transfer{}).Select("SUM(`out`) AS n").Where("created_at > ? AND server_id = ?", u.GetTransferDurationStart(), server.ID).Scan(&res)
 			src += float64(res.N)
 		}
 	case "transfer_all_cycle":
 		src = float64(server.State.NetOutTransfer - uint64(server.PrevHourlyTransferOut) + server.State.NetInTransfer - uint64(server.PrevHourlyTransferIn))
-		if u.CycleInterval != 1 {
+		if u.CycleInterval != nil {
 			var res NResult
 			db.Model(&Transfer{}).Select("SUM(`in`+`out`) AS n").Where("created_at > ?  AND server_id = ?", u.GetTransferDurationStart(), server.ID).Scan(&res)
 			src += float64(res.N)
@@ -146,7 +147,7 @@ func (u *Rule) Snapshot(cycleTransferStats *CycleTransferStats, server *Server,
 		cycleTransferStats.NextUpdate[server.ID] = u.NextTransferAt[server.ID]
 		// 自动更新周期流量展示起止时间
 		cycleTransferStats.From = u.GetTransferDurationStart()
-		cycleTransferStats.To = cycleTransferStats.From.Add(time.Hour * time.Duration(u.CycleInterval))
+		cycleTransferStats.To = u.GetTransferDurationEnd()
 	}
 
 	if u.Type == "offline" && float64(time.Now().Unix())-src > 6 {
@@ -163,6 +164,25 @@ func (rule Rule) IsTransferDurationRule() bool {
 }
 
 func (rule Rule) GetTransferDurationStart() time.Time {
-	interval := 3600 * int64(rule.CycleInterval)
-	return time.Unix(rule.CycleStart.Unix()+(time.Now().Unix()-rule.CycleStart.Unix())/interval*interval, 0)
+	expr := cronexpr.MustParse(rule.CycleInterval)
+	durationStart := rule.CycleInterval
+	nextTime := expr.Next(rule.CycleStart)
+	for nextTime.Before(time.Now()) {
+		durationStart = nextTime
+		nextTime = expr.Next(rule.CycleStart)
+	}
+	// TODO: catch the err from parse String and Next function.
+	return time.Unix(durationStart.Unix, 0)
+}
+
+func (rule Rule) GetTransferDurationEnd() time.Time {
+	expr := cronexpr.MustParse(rule.CycleInterval)
+	durationStart := rule.CycleInterval
+	nextTime := expr.Next(rule.CycleStart)
+	for nextTime.Before(time.Now()) {
+		durationStart = nextTime
+		nextTime = expr.Next(rule.CycleStart)
+	}
+	// TODO: catch the err from parse String and Next function.
+	return time.Unix(nextTime.Unix, 0)
 }
diff --git a/service/dao/alertsentinel.go b/service/dao/alertsentinel.go
index bdd1767..17760a0 100644
--- a/service/dao/alertsentinel.go
+++ b/service/dao/alertsentinel.go
@@ -38,10 +38,11 @@ func addCycleTransferStatsInfo(alert *model.AlertRule) {
 		}
 		if AlertsCycleTransferStatsStore[alert.ID] == nil {
 			from := alert.Rules[j].GetTransferDurationStart()
+			to := alert.Rules[j].GetTransferDurationEnd()
 			AlertsCycleTransferStatsStore[alert.ID] = &model.CycleTransferStats{
 				Name:       alert.Name,
 				From:       from,
-				To:         from.Add(time.Hour * time.Duration(alert.Rules[j].CycleInterval)),
+				To:         to,
 				Max:        uint64(alert.Rules[j].Max),
 				Min:        uint64(alert.Rules[j].Min),
 				ServerName: make(map[uint64]string),