diff --git a/config/config.go b/config/config.go
index 2b8e1ea..c4da943 100755
--- a/config/config.go
+++ b/config/config.go
@@ -4,14 +4,16 @@ import (
 	"local/args"
 	"local/sandbox/contact/contact"
 	"os"
+	"time"
 )
 
 var (
-	Feed    string
-	Root    string
-	To      string
-	Subject string
-	Emailer *contact.Emailer
+	Feed     string
+	Root     string
+	To       string
+	Subject  string
+	Emailer  *contact.Emailer
+	Interval time.Duration
 )
 
 func init() {
@@ -28,6 +30,7 @@ func init() {
 
 	as.Append(args.STRING, "feed", "feed URL", "https://www.youtube.com/feeds/videos.xml?channel_id=UCwX0AEx-qIhQ9kgtlNhyIXw")
 	as.Append(args.STRING, "root", "root to save videos", "/tmp")
+	as.Append(args.DURATION, "interval", "check interval", time.Hour)
 
 	if err := as.Parse(); err != nil {
 		panic(err)
diff --git a/main.go b/main.go
index 99f0320..01e8b8c 100755
--- a/main.go
+++ b/main.go
@@ -18,7 +18,7 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	interval := time.Minute * 30
+	interval := config.Interval
 	for true {
 		err := do(client)
 		if err != nil {