Calculate difference between two dates from DateTimePicker using C# in Windows Forms Application

Hi lingtyson,

Check this example. Now please take its reference and correct your code.

Code

C#

private void dateTimePicker1_ValueChanged(object sender, EventArgs e)
{
    DateTime inTime = Convert.ToDateTime(dateTimePicker1.Text);
    DateTime outTime = Convert.ToDateTime(dateTimePicker2.Text);
    if (outTime >= inTime)
    {
        textBox1.Text = outTime.Subtract(inTime).Days.ToString();
    }
}

VB.Net

Private Sub dateTimePicker1_ValueChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim inTime As DateTime = Convert.ToDateTime(dateTimePicker1.Text)
    Dim outTime As DateTime = Convert.ToDateTime(dateTimePicker2.Text)
    If outTime >= inTime Then
        textBox1.Text = outTime.Subtract(inTime).Days.ToString()
    End If
End Sub

Screenshot