Android Question Hours and minutes between two times [Solved]

Dim a As String = "12:15"
    Dim b As String= "08:45"
    Dim h , m As Int
    Dim t1() As String =Regex.Split(":",a)
    Dim t2() As String =Regex.Split(":",b)
    Dim t As Int = t1(0) *60 +t1(1) -t2(0) * 60 - t2(1)    
    h=Floor(t/60)
    m= t Mod 60
    Log($"${h}:${m}"$)  'will display 3:30

Sub Button1_Click
    Dim PerDiff As Period
    Dim StartHrs, StartMin, EndHrs, EndMin As Int
    
    StartHrs = edtStartHrs.Text
    StartMin = edtStartMin.Text
    EndHrs = edtEndHrs.Text
    EndMin = edtEndMin.Text
    
    Dim TimeA As Long = DateUtils.SetDateAndTime(2020, 10, 10, StartHrs, StartMin, 0)
    Dim TimeB As Long = DateUtils.SetDateAndTime(2020, 10, 10, EndHrs, EndMin, 0)
    
    PerDiff = DateUtils.PeriodBetween(TimeA, TimeB)
    
    lblAnswer.Text = PerDiff.Hours & ":" & PerDiff.Minutes

End Sub

Sub CalcHrsMins(shrs As Int, smins As Int, ehrs As Int, emins As Int)
    Dim stotalMins As Int = ((shrs * 60) + smins)
    Dim etotalmins As Int = ((ehrs * 60) + emins)
    Dim ResultMins As Int = etotalmins - stotalMins
    Log("result " & ResultMins)
    HoursDiff = ResultMins / 60
    MinsDiff = ResultMins Mod 60
End Sub