You convert the text of the textbox to datetime.
Then you can retrieve the required details from it.
This is how you get hour and time from it.
Protected Sub Button1_Click(sender As Object, e As EventArgs)
Dim dt As DateTime = Convert.ToDateTime(TextBox1.Text)
Dim hours As Integer = dt.Hour
Dim longTimeString As String = dt.ToLongTimeString()
Dim shortTimeString As String = dt.ToShortTimeString()
End Sub
I suggest you to go through the DateTime class on MSDN -
here
PS: I wrote the program in C# and converted it to vb using online converters.
Edit: Added output.