"Insert Date" auto-updating?

In the old Appleworks, you could easily set the current date not only to show today's date, but to be auto-updating; that is, to always set itself to today's date whenever the saved document or template is opened. In Pages, there is a way to set it to today's date, but you have to remember to do it each time, or it will be set to the wrong date.

In the attached screenshot, there is a button for "Set to Now" but nothing for automatically setting it to the current date when opened. Is there a way to do this?