#[clap(long = "timestamp")]

    #[clap(long = "timestamp", validator = timestamp_validator)]

fn timestamp_validator(s: &str) -> Result<(), &'static str> {
    if let Ok(t) = s.parse() {
        if chrono::NaiveDateTime::from_timestamp_opt(t, 0).is_some() {
            return Ok(())
        }
    }
    Err("Could not parse timestamp")
}