fn parse_hour(hour: &[u8]) -> Option<u8> {
    match parse_2_digits(hour) {
        Some(hour) if hour < 24 => Some(hour),
        _ => None,
    }
}
/// Parse a 2-digit hour
Parse a 2-digit hour
Parse a 2 - digit hour
fn parse_hour(hour: &[u8]) -> Option<u8> {
    match parse_2_digits(hour) {
        Some(hour) if hour < 24 => Some(hour),
        _ => None,
    }
}
fn parse_hour ( hour : & [ u8 ] ) -> Option < u8 > { match parse_2_digits ( hour ) { Some ( hour ) if hour < 24 => Some ( hour ) , _ => None , } }
Parse a 2-digit hour
Parse a 2 - digit hour
hour
&[u8]