Dim hh, mm As String
Dim dtDate1 As Date = "11:30"
Dim dtDate2 As Date = "12:15"
hh = DateDiff(DateInterval.Hour, dtDate1, dtDate2) 'จำนวนชั่วโมง
mm = DateDiff(DateInterval.Minute, dtDate1, dtDate2) Mod 60 'จำนวนนาที
Dim ts As New TimeSpan(CInt(hh), CInt(mm), CInt("0"))
Dim tTime As String = FormatDateTime(ts.ToString, DateFormat.ShortTime).ToString
LabelControl1.Text = tTime