Option Explicit

Private Enum BOOL
   FALSE_BOOL
   TRUE_BOOL
End Enum

Private Declare Function SetTimer Lib "user32" ( _
   ByVal hWnd As Long, ByVal nIDEvent As Timer, _
   ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Private Declare Function KillTimer Lib "user32" ( _
   ByVal hWnd As Long, ByVal nIDEvent As Timer) As BOOL

Private m_hWnd As Long
Private m_nInterval As Long
Private m_fEnabled As Boolean
Private m_fRunning As Boolean

Public Event Timer()

Public Property Get hWnd() As Long
 hWnd = m_hWnd
End Property

Public Property Let hWnd(ByVal hwndOwner As Long)
 Dim lResult As Long
 If m_fRunning Then
    lResult = KillTimer(m_hWnd, Me)
    Debug.Assert lResult = FALSE_BOOL
    lResult = SetTimer(hwndOwner, Me, m_nInterval, AddressOf TimerProc)
    m_fRunning = lResult = 0&
    Debug.Assert m_fRunning
 End If
 m_hWnd = hwndOwner
End Property


Public Property Get Enabled() As Boolean
 Enabled = m_fEnabled
End Property

Public Property Let Enabled(ByVal fEnabled As Boolean)
 Dim lResult As Long
 If m_fEnabled = fEnabled Then Exit Property
 If fEnabled Then
    If m_nInterval > 0 Then
       lResult = SetTimer(m_hWnd, Me, m_nInterval, AddressOf TimerProc)
       m_fRunning = lResult <> 0&
       Debug.Assert m_fRunning
    End If
 Else
    If m_fRunning Then
       lResult = KillTimer(m_hWnd, Me)
       Debug.Assert lResult <> FALSE_BOOL
       m_fRunning = False
    Else
       Debug.Assert False
    End If
 End If
 m_fEnabled = fEnabled
End Property


Public Property Get Interval() As Long
 Interval = m_nInterval
End Property

Public Property Let Interval(ByVal nInterval As Long)
 Dim lResult As Long
 Select Case nInterval
 Case Is > 0:
    m_nInterval = nInterval
    If m_fEnabled Then
       lResult = SetTimer(m_hWnd, Me, nInterval, AddressOf TimerProc)
       m_fRunning = lResult <> 0&
       Debug.Assert m_fRunning
    End If
 Case 0:
    If m_fRunning Then
       lResult = KillTimer(m_hWnd, Me)
       Debug.Assert lResult <> FALSE_BOOL
       m_fRunning = False
    End If
    m_nInterval = 0
 Case Else:
    Err.Raise 5
 End Select
End Property


Friend Sub WM_TIMER_Notify()
 Debug.Print VBA.Timer(), "WM_TIMER_Notify"
 RaiseEvent Timer
End Sub


Private Sub Class_Initialize()
 m_hWnd = hWndAccessApp 'Это для MS Access. Для других VBA-хостов hWnd главного окна, либо же просто 0
End Sub

Private Sub Class_Terminate()
 Enabled = False
End Sub

Option Explicit

Public Sub TimerProc(ByVal hWnd As Long, ByVal uMsg As Long, _
                     ByVal idEvent As Timer, ByVal dwTime As Long)
 idEvent.WM_TIMER_Notify
End Sub