按时双重格式化

如何设置 TotalHours 或者我需要做什么才能得到结果 txtBoxMonatstotal 由于 93.3 . 这是我的代码:

private void calendar1_MonthChanged(object sender, EventArgs e)
{
    DateTime start = new DateTime(calendar1.CurrentDate.Year, calendar1.CurrentDate.Month, 1);
    DateTime stop = new DateTime(calendar1.CurrentDate.Year, calendar1.CurrentDate.Month, 1).AddMonths(1).AddDays(-1);
    int numberOfWorkDays = GetNumberOfWorkingDays(start, stop);

    double shouldWorkPerMonth = tag_durschnit * numberOfWorkDays;
    double workedPerMonth = workingHours.Where(x => x.Key.Date.Year == start.Year && x.Key.Month == start.Month).Sum(x => x.Value.TotalHours);
    double saldo = workedPerMonth - shouldWorkPerMonth;

    txtBoxMonatstotal.Text = workedPerMonth.ToString();
    txtBoxSollzeit.Text = shouldWorkPerMonth.ToString();
    txtBoxSaldo.Text = saldo.ToString();

}

当前结果如下所示:
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谢谢你的帮助