pkg/template/metadata: use numeric timezone offsets

pkg/template/metadata.go

@@ -25,7 +25,7 @@ func (m Metadata) String() []string {
 type JSONTime time.Time
 
 const (
-	timeFormat = "Mon Jan 2 15:04 -0700 MST 2006"
+	timeFormat = "Mon Jan 2 15:04 -0700 +07 2006"
 )
 
 // NewTime returns a new JSONTime containing the current time.