diff --git a/collector/auto_backup_test.go b/collector/auto_backup_test.go
index 038131f..c072d84 100644
--- a/collector/auto_backup_test.go
+++ b/collector/auto_backup_test.go
@@ -89,10 +89,10 @@ func TestAutoBackupCollector_Collect(t *testing.T) {
 						Name:                    "AutoBackup",
 						DiskID:                  201,
 						MaximumNumberOfArchives: 3,
-						BackupSpanWeekdays: []types.EBackupSpanWeekday{
-							types.BackupSpanWeekdays.Sunday,
-							types.BackupSpanWeekdays.Monday,
-							types.BackupSpanWeekdays.Tuesday,
+						BackupSpanWeekdays: []types.EDayOfTheWeek{
+							types.DaysOfTheWeek.Sunday,
+							types.DaysOfTheWeek.Monday,
+							types.DaysOfTheWeek.Tuesday,
 						},
 						Tags:        types.Tags{"tag1", "tag2"},
 						Description: "desc",
@@ -126,10 +126,10 @@ func TestAutoBackupCollector_Collect(t *testing.T) {
 						Name:                    "AutoBackup",
 						DiskID:                  201,
 						MaximumNumberOfArchives: 3,
-						BackupSpanWeekdays: []types.EBackupSpanWeekday{
-							types.BackupSpanWeekdays.Sunday,
-							types.BackupSpanWeekdays.Monday,
-							types.BackupSpanWeekdays.Tuesday,
+						BackupSpanWeekdays: []types.EDayOfTheWeek{
+							types.DaysOfTheWeek.Sunday,
+							types.DaysOfTheWeek.Monday,
+							types.DaysOfTheWeek.Tuesday,
 						},
 						Tags:        types.Tags{"tag1", "tag2"},
 						Description: "desc",
@@ -176,10 +176,10 @@ func TestAutoBackupCollector_Collect(t *testing.T) {
 						Name:                    "AutoBackup",
 						DiskID:                  201,
 						MaximumNumberOfArchives: 3,
-						BackupSpanWeekdays: []types.EBackupSpanWeekday{
-							types.BackupSpanWeekdays.Sunday,
-							types.BackupSpanWeekdays.Monday,
-							types.BackupSpanWeekdays.Tuesday,
+						BackupSpanWeekdays: []types.EDayOfTheWeek{
+							types.DaysOfTheWeek.Sunday,
+							types.DaysOfTheWeek.Monday,
+							types.DaysOfTheWeek.Tuesday,
 						},
 						Tags:        types.Tags{"tag1", "tag2"},
 						Description: "desc",
diff --git a/collector/functions.go b/collector/functions.go
index 8d7ab8d..2adb0a1 100644
--- a/collector/functions.go
+++ b/collector/functions.go
@@ -32,15 +32,11 @@ func flattenStringSlice(values []string) string {
 	return fmt.Sprintf(",%s,", strings.Join(values, ","))
 }
 
-func flattenBackupSpanWeekdays(values []types.EBackupSpanWeekday) string {
+func flattenBackupSpanWeekdays(values []types.EDayOfTheWeek) string {
 	if len(values) == 0 {
 		return ""
 	}
-
-	// sort
-	sort.Slice(values, func(i, j int) bool {
-		return backupSpanWeekdaysOrder[values[i]] < backupSpanWeekdaysOrder[values[j]]
-	})
+	types.SortDayOfTheWeekList(values)
 
 	var strValues []string
 	for _, v := range values {
@@ -48,13 +44,3 @@ func flattenBackupSpanWeekdays(values []types.EBackupSpanWeekday) string {
 	}
 	return fmt.Sprintf(",%s,", strings.Join(strValues, ","))
 }
-
-var backupSpanWeekdaysOrder = map[types.EBackupSpanWeekday]int{
-	types.BackupSpanWeekdays.Sunday:    0,
-	types.BackupSpanWeekdays.Monday:    1,
-	types.BackupSpanWeekdays.Tuesday:   2,
-	types.BackupSpanWeekdays.Wednesday: 3,
-	types.BackupSpanWeekdays.Thursday:  4,
-	types.BackupSpanWeekdays.Friday:    5,
-	types.BackupSpanWeekdays.Saturday:  6,
-}
diff --git a/examples/fake/generate-fake-store-json/main.go b/examples/fake/generate-fake-store-json/main.go
index 0f5400a..050f69c 100644
--- a/examples/fake/generate-fake-store-json/main.go
+++ b/examples/fake/generate-fake-store-json/main.go
@@ -87,10 +87,10 @@ func createAutoBackup(caller iaas.APICaller) {
 	_, err = backupOp.Create(context.Background(), "is1a", &iaas.AutoBackupCreateRequest{
 		Name:   "example",
 		DiskID: disk.ID,
-		BackupSpanWeekdays: []types.EBackupSpanWeekday{
-			types.BackupSpanWeekdays.Monday,
-			types.BackupSpanWeekdays.Wednesday,
-			types.BackupSpanWeekdays.Friday,
+		BackupSpanWeekdays: []types.EDayOfTheWeek{
+			types.DaysOfTheWeek.Monday,
+			types.DaysOfTheWeek.Wednesday,
+			types.DaysOfTheWeek.Friday,
 		},
 		MaximumNumberOfArchives: 5,
 		Description:             "desc",
@@ -135,8 +135,8 @@ func createDatabase(caller iaas.APICaller) {
 		BackupSetting: &iaas.DatabaseSettingBackup{
 			Rotate: 3,
 			Time:   "00:00",
-			DayOfWeek: []types.EBackupSpanWeekday{
-				types.BackupSpanWeekdays.Sunday,
+			DayOfWeek: []types.EDayOfTheWeek{
+				types.DaysOfTheWeek.Sunday,
 			},
 		},
 		Name:        "example",
diff --git a/go.mod b/go.mod
index 05bac06..579c00f 100644
--- a/go.mod
+++ b/go.mod
@@ -6,8 +6,8 @@ require (
 	github.com/prometheus/client_golang v1.13.0
 	github.com/prometheus/client_model v0.2.0
 	github.com/sacloud/api-client-go v0.2.1
-	github.com/sacloud/iaas-api-go v1.2.1
-	github.com/sacloud/iaas-service-go v1.2.0
+	github.com/sacloud/iaas-api-go v1.3.1
+	github.com/sacloud/iaas-service-go v1.3.1
 	github.com/sacloud/packages-go v0.0.5
 	github.com/stretchr/testify v1.8.0
 )
diff --git a/go.sum b/go.sum
index 9125eb7..62af721 100644
--- a/go.sum
+++ b/go.sum
@@ -274,10 +274,10 @@ github.com/sacloud/api-client-go v0.2.1 h1:jl02ZG6cM+mcH4eDYg0cxCFFuTOVTOjUCLYL4
 github.com/sacloud/api-client-go v0.2.1/go.mod h1:8fmYy5OpT3W8ltV5ZxF8evultNwKpduGN4YKmU9Af7w=
 github.com/sacloud/go-http v0.1.2 h1:a84HkeDHxDD1vIA6HiOT72a3fwwJueZBwuGP6zVtEJU=
 github.com/sacloud/go-http v0.1.2/go.mod h1:gvWaT8LFBFnSBFVrznOQXC62uad46bHZQM8w+xoH3eE=
-github.com/sacloud/iaas-api-go v1.2.1 h1:QuIWelF6KSQLPeDJy4HMNbQND7XQlZyjyRnc8lGiG1I=
-github.com/sacloud/iaas-api-go v1.2.1/go.mod h1:+ScynU5gBwq+rA7qw6EppIQwRhXSMkGoRkZlFIj5v+g=
-github.com/sacloud/iaas-service-go v1.2.0 h1:cfVAG1IPVV0gRyZ+onPq9qOhsBV8AEAM1A3krU1P2cs=
-github.com/sacloud/iaas-service-go v1.2.0/go.mod h1:mi88b6BqTtYqVjSitdVg5qSiyINdhuKdShY+3MFWIwQ=
+github.com/sacloud/iaas-api-go v1.3.1 h1:UmP9r4NNd1YucmeTzzJtsFsT9d/RYvJn2tP+HmC4yMk=
+github.com/sacloud/iaas-api-go v1.3.1/go.mod h1:CoqpRYBG2NRB5xfqTfZNyh2lVLKyLkE/HV9ISqmbhGc=
+github.com/sacloud/iaas-service-go v1.3.1 h1:ltMadQPUGzpSHD3k6XrqWy1XykIgZFseu/AA67qHjAI=
+github.com/sacloud/iaas-service-go v1.3.1/go.mod h1:2mkOWoEk8gdHuxShI6RLssw1g4Sd6vc92ErcNaL2vPk=
 github.com/sacloud/packages-go v0.0.5 h1:NXTQNyyp/3ugM4CANtLBJLejFESzfWu4GPUURN4NJrA=
 github.com/sacloud/packages-go v0.0.5/go.mod h1:XWMBSNHT9YKY3lCh6yJsx1o1RRQQGpuhNqJA6bSHdD4=
 github.com/sebdah/goldie v1.0.0/go.mod h1:jXP4hmWywNEwZzhMuv2ccnqTSFpuq8iyQhtQdkkZBH4=