Option Explicit

Const roundMin = 5

Private Sub Form_Load()
  Timer1.Interval = 1000
End Sub

Private Sub Command1_Click(index As Integer)
  Select Case index
    Case 1
      Label2.Caption = Format$(roundTime(time), "hh:mm")
    Case Else
      Unload Me
      End
  End Select
End Sub

Private Sub Timer1_Timer()
  Label1.Caption = Format$(time, "hh:mm:ss")
End Sub

Function roundTime(time As Variant) As Double
  Dim min As Integer, std As Integer

  min = Minute(time)
  std = Hour(time)
  min = CInt(min / roundMin) * roundMin
  If min = 60 Then
     min = 0: std = std + 1
     If std = 24 Then std = 0
  End If
  roundTime = TimeSerial(std, min, 0)
End Function