Calculate time difference between two dates

Public Function TimeDifference(ByVal fd As String, ByVal ld As String) As String

fd=first date
ld=last date
simply pass fd and ld in datediff function given below

Public Function TimeDifference(ByVal fd As String, ByVal ld As String) As String
        Dim lastcomctonday As String = DateDiff("d", fd, ld)
        Dim lastcomcton As String = DateDiff("n", fd, ld)
        'Dim lastcomsec As String = DateDiff("s", fd, ld)
        If Val(lastcomcton) < 60 Then
            timedif = "After Complaint: " & "0 Hours " & lastcomcton & " Minutes Later"   '"Same Day " &
        ElseIf Val(lastcomcton) / 60 < 24 Then
            timedif = "After Complaint: " & CStr(Math.Round(Val(lastcomcton) / 60, 0)) & " Hour(s) Later"  '"Same Day " &
        Else
            timedif = "After Complaint: " & lastcomctonday & " Days Later"
        End If
        Return timedif
    End Function