#[error("can not convert chrono milliseconds: {0}")]
    ConvertDuration(std::num::TryFromIntError),

                row.push(format_duration(entry.time_start, entry.time_finished))

                row.push(format_duration(entry.time_start, entry.time_finished)?)

fn format_duration(time_start: DateTime<Utc>, time_finished: DateTime<Utc>) -> String {

fn format_duration(
    time_start: DateTime<Utc>,
    time_finished: DateTime<Utc>,
) -> Result<String, Error> {

    let duration_std = std::time::Duration::from_millis(duration_ms.try_into().unwrap());

    let duration_std =
        std::time::Duration::from_millis(duration_ms.try_into().map_err(Error::ConvertDuration)?);

    humantime::format_duration(duration_std)

    Ok(humantime::format_duration(duration_std)

        .replace(" ", "")

        .replace(" ", ""))