Auto Open macro

[siray13]

How do I get a macro to start when I open a workbook? I have the following code that works fine when I run it. Any help would be appreciated. Thank you in advance.

Option Explicit
Public setDate As Date
Sub UpdateTime()
    setDate = Now() + TimeValue("00:00:30")
    Application.OnTime setDate, "TimeUp"
    ActiveWorkbook.Save
End Sub