diff --git a/main.go b/main.go
index e8ad466..24e3615 100644
--- a/main.go
+++ b/main.go
@@ -53,7 +53,7 @@ func connectMongo() {
 }
 
 func usage() {
-	fmt.Println("Usage: imp_mongo -d <date> -r <date range> -m <mongodb uri> -l <logfile>\n")
+	fmt.Println("Usage: imp_mongo -d <date (yyyy-mm-dd:hh)> -r <date range (HHh)> -m <mongodb uri> -l <logfile>\n")
 	os.Exit(0)
 }