C#

public bool bCodeChange1; // Used to stop double check of NumericUpDown
public bool bCodeChange2; // Used to stop Double check for DateTimePicker

/// <summary>
/// Sets DateTime to have Time At: 00:00:00:00 (HH:MM:SS:mil)
/// </summary>
/// <param name="time"></param>
/// <returns></returns>
private DateTime RemoveTime(DateTime time)
{
    time = time.AddHours(-time.Hour);
    time = time.AddMilliseconds(-time.Millisecond);
    time = time.AddMinutes(-time.Minute);
    time = time.AddSeconds(-time.Second);
    return time;
}

private void dateTimePickerDateDeadLine_ValueChanged(object sender, EventArgs e)
{
    DateTime dtDateDeadLine = dateTimePickerDateDeadLine.Value;
    DateTime dtDateReciet = dateTimePickerDateReciet.Value;
    dtDateDeadLine = RemoveTime(dtDateDeadLine );
    dtDateReciet = RemoveTime(dtDateReciet );

    if (dtDateRecit >= dtDateDeadLine )
    {
        MessageBox.Show("DeadLine need to be at least one day ahead of Reciet", "Račun", MessageBoxButtons.OK);
        dateTimePickerDateDeadLine.Value = dtDateReciet.AddDays(1);
        return;
    }

    if (bCodeChange2)
    {
        bCodeChange2 = false;
        return;
    }
    bCodeChange1 = true;

// Here lies the problem
// dtDateDeadLine: {30.11.2009 0:00:00}
// dtDateReciet: {1.12.2009 0:00:00}

// All works whell, unless i select at date, with same dates.
// In Both cases (Normaly and not Normaly) below line, gets the same values(As Above), but sometimes it gives 2 or 1.
// It gives a One in normal whay, however it will return true if this statemnt executes: 'if (dtDateRecit >= dtDateDeadLine )'
    numericUpDownDaysTillDeadLine.Value = dtDateDeadLine.Subtract(dtDateReciet).Days + 1; 
}

private void numericUpDownDaysTillDeadLine_ValueChanged(object sender, EventArgs e)
{
    if (bCodeChange1)
    {
        bCodeChange1 = false;
        return;
    }
    bCodeChange2 = true;
    numericUpDownDaysTillDeadLine.Value = dateTimePickerDateReciet.Value.AddDays(Convert.ToDouble(numericUpDownDaysTillDeadLine.Value));
}

//Resets the browser to the previous page when an item is deleted.
            if (cboSP_Site.SelectedIndex == -1 && inttmpSP != -1)
            {
                WebBrowser1.GoBack();
            }
            else if (cboWS.SelectedIndex == -1 && inttmpWS != -1)
            {
                WebBrowser1.GoBack();
            }
            else if (cboFolder.SelectedIndex == -1 && inttmpF != -1)
            {
                WebBrowser1.GoBack();
            }