@@ -447,7 +447,7 @@ func cmd(b *Builder, args []string, attributes map[string]bool, original string)

 }

 // parseOptInterval(flag) is the duration of flag.Value, or 0 if

-// empty. An error is reported if the value is given and is not positive.

+// empty. An error is reported if the value is given and less than 1 second.

 func parseOptInterval(f *Flag) (time.Duration, error) {

 	s := f.Value

 	if s == "" {

@@ -457,8 +457,8 @@ func parseOptInterval(f *Flag) (time.Duration, error) {

 	if err != nil {

 		return 0, err

 	}

-	if d <= 0 {

-		return 0, fmt.Errorf("Interval %#v must be positive", f.name)

+	if d < time.Duration(time.Second) {

+		return 0, fmt.Errorf("Interval %#v cannot be less than 1 second", f.name)

 	}

 	return d, nil

 }