Hi Kevin,

Thanks a mil for your patience. I think I have it working with your first part of code. 
Dim ws As Worksheet
For Each ws In ThisWorkbook.Worksheets
    If ws.Name <> "Splash" Then ws.Visible = xlVeryHidden
Next ws
The second part seems to be causing errors. Do I require this second part for any reason? Sheets are already programmed to unhide depending on who logs in. Your bit ensures all sheets return to hidden when timer runs out. I just want to make sure I'm not leaving myself open by leaving the second part out.

For Each ws In ThisWorkbook.Worksheets
    ws.Visible = xlSheetVisible
Next ws
Option Explicit
'Module1
Public bGblInhibitTimers As Boolean
Public RunWhen As Double
Public RunStatusBarWhen As Double
Public Const NUM_MINUTES = 10
Public Const NUM_SECONDS = 0
Public Const STATUS_BAR_REFRESH_TIME_IN_SECONDS = 1

Public Sub StopTimers()
  'This is used for debugging purposes to shut down the timers

  bGblInhibitTimers = True
  On Error Resume Next
  Application.OnTime RunWhen, "SaveAndClose", , False
  Application.OnTime RunStatusBarWhen, "TimeTilExitTimer", , False
  On Error GoTo 0
 
  Application.StatusBar = "Timers stopped by StopTimers()."


End Sub

Public Sub SaveAndClose()

  'Tell the time remaining timer to stop
  bGblInhibitTimers = True
  
  On Error Resume Next
  Application.OnTime RunStatusBarWhen, "TimeTilExitTimer", , False
  On Error GoTo 0
  'Debug.Print "bGblInhibitTimers = true in SaveAndClose() at " & Now
  
  'Return control of the Status Bar to Excel
  Application.StatusBar = ""
  Application.StatusBar = False
  Sheets("Splash").Visible = xlSheetVisible
Dim ws As Worksheet
For Each ws In ThisWorkbook.Worksheets
    If ws.Name <> "Splash" Then ws.Visible = xlVeryHidden
Next ws
  ThisWorkbook.Close savechanges:=True
End Sub

Sub TestTime()
  RunWhen = Now + TimeSerial(0, NUM_MINUTES, NUM_SECONDS)
  Debug.Print Format(RunWhen, "mm/dd/yy hh:mm:ss AM/PM")
End Sub
Sub TimeTilExitTimer()
  'This displays a time until exit message

  Const SECONDS_PER_DAY = 86400#
  Const SECONDS_PER_MINUTE = 60#
  
  Dim sMessage As String
  Dim ySecondsTimeToExit As Double
  Dim yMinutes As Double
  Dim ySeconds As Double

  Dim myTime As Date
  
  'Get the current date and time
  myTime = Now()
  
  'Calculate the number of seconds remaining to shut down
  ySecondsTimeToExit = SECONDS_PER_DAY * (RunWhen - myTime)
  
  'Check for Integrity Error - RunWhen = 0
  'Should Never Happen - Shut Down the refresh timer
  If ySecondsTimeToExit < 0 Then
    bGblInhibitTimers = True
    Application.StatusBar = "Software Integrity Error - Time Remaining Display discontinued."
  End If
  
  If ySecondsTimeToExit <= 99 Then
    sMessage = "Program will time out and exit in " & Format(ySecondsTimeToExit, "0") & " Seconds."
  Else
    yMinutes = Int(ySecondsTimeToExit / SECONDS_PER_MINUTE)
    ySeconds = Int(ySecondsTimeToExit - 60 * yMinutes)
    If yMinutes > 0 And ySeconds >= 60 Then
      yMinutes = yMinutes + 1
      ySeconds = ySeconds - 60
    End If
    
    sMessage = "Program will time out and exit at " & Format(RunWhen, "hh:mm:ss AM/PM") & " in " & _
                Format(yMinutes, "0") & " Minutes " & Format(ySeconds, "0") & " Seconds."
  End If
  
  
  If bGblInhibitTimers = True Then
    'Return control of the Status Bar to Excel
    Application.StatusBar = ""
    Application.StatusBar = False
    'Debug.Print "bGblInhibitTimers = true in TimeTilExitTimer() at " & Now

  Else
    Application.DisplayStatusBar = True
    Application.StatusBar = sMessage

    RunStatusBarWhen = Now + TimeSerial(0, 0, STATUS_BAR_REFRESH_TIME_IN_SECONDS)
    Application.OnTime RunStatusBarWhen, "TimeTilExitTimer", , True
    'Debug.Print "bGblInhibitTimers = false in TimeTilExitTimer() at " & Now
  End If

End Sub