The calc must be unstated for it to automatically update. This setting is an option when you configure your field.Unstored I meant!
But if you are using today's date in other field's calculations, you don't need any such field at all, you can just refer to Get ( CurrentDate ) in those other calculations.
And Rick's advice not to store the calculation result remains advice that you must follow to see these calculations update automatically as time passes and today's date changes.
Thank you Rick and Phil!