OnTime Application keeps opening my Workbook

-In ThisWorkbook-
 
Private Sub Workbook_Open()
 
Dim CalcDailyEnroll As Range
Dim CalcDailyPay As Range
Dim aRow As Long
 
'This Macro zips file once this number minutes after opening
  Application.OnTime Now + TimeValue("00:05:00"), "Timed_Macro"
 
Application.Calculation = xlManual ' Turns Calculation to Manual
Application.CalculateBeforeSave = False ' Turns calculate before Save Off
ActiveWorkbook.EnableAutoRecover = False ' Turns Off autorecovery
 
MsgBox "This File (if Not ReadOnly) is" & Chr(13) & Chr(13) _
& "a.  Automatically Saved & Zipped about every 90 minutes &    " & Chr(13) & Chr(13) _
& "b.  Saved & Zipped automatically on closure   "
 
    Range("CalcDailyEnroll").Cells.Calculate
    Range("CalcDailyPay").Cells.Calculate
 
'Goto last row in Enroll spreadsheet
Cells(65536, 2).Select
Selection.End(xlUp).Select
aRow = ActiveCell.Row
ActiveWindow.ScrollRow = aRow - 5
 
End Sub
 
Private Sub Workbook_BeforeClose(Cancel As Boolean)
 ' This macro turns off the timer otherwise spreadsheet will open even after it is closed and execute the above macro
   
   Application.OnTime dTime, "Timed_Macro", False
   
End Sub
 
-In Module-
 
Sub Timed_Macro()
 
    dTime = Now + TimeValue("01:30:00")  'Format for time is hh:mm:ss  
    Application.OnTime dTime, "Timed_Macro" 'ensure this is this macros name
 
'Stops autosave on readonly copies
    If ThisWorkbook.ReadOnly Then
        ''MsgBox "read-only"
        Else
'Save a zipped copy of this workbook with time stamp and then move it to backup directory
        ProtectALL
        Zip_ThisWorkbook
    End If
End Sub