Access 2013 - Auto Log Out of the ACCDE users

I built it in VBA.
I have a form that loads hidden as one of the first things the app does.
It has some code
Here's the declarations.
I want things to close at 9 PM

Option Compare Database
Option Explicit
Const timeToRun As Date = #9:00:00 PM#
Const DelayFromLastActivity As Long = 5
'minutes of delay

Select allOpen in new window

some OnLoad code, to set a timer interval

Private Sub Form_Load()
If DateDiff("s", Time(), timeToRun) < DelayFromLastActivity Then
    TheInterval = DelayFromLastActivity * 60 * 1000
Else
    TheInterval = DateDiff("s", Time(), timeToRun) * 1000
End If
Me.TimerInterval = TheInterval
DontSkipMessage = True
End Sub

Select allOpen in new window

Some code to quit the application if the timer goes off
I have a message to users when they try to quit allowing a cancel.
They always click the wrong X

Private Sub Form_Unload(Cancel As Integer)
Dim response As Integer
If DontSkipMessage = True Then
    response = MsgBox("Did you really intend to quit The Program? Yes to Quit, no to remain in The Program", vbYesNo + vbCritical, "Quit?")
    If response = vbNo Then
        Cancel = True
        If Application.CurrentProject.AllForms("frmStartupScreen").IsLoaded = False Then
            DoCmd.OpenForm "frmStartupScreen"
        End If
    End If
End If
End Sub

Select allOpen in new window

In a code module, I have

Global DontSkipMessage As Boolean
Public TheInterval As Long

Select allOpen in new window

Then in any of the forms likely to be active, I have code to bump theInterval back past 9:05 PM if they are working on the form.
The locations of that code vary because of the nature of the forms I monitor, but it is basically like the OnLoad code.

If this timer event goes off, the app quits.
And the timer event only happens once!
No Timer heartbeat grief.