The Date
Menu of the
Add Glossary Entry
window
enables you to embed date
macros
in glossary Phrase Entries:

You can select:
yesterday's date
today's date
tomorrow's date
in the Short Date or Long Date formats. These formats are defined in the Region Control Panel applet.
Or you may also use alternate date formats in your expansions with the Custom Date macros.
Note that dates displayed to the right of the Yesterday, Today, Tomorrow menu items, give you a preview of dates, as they would expand right now. These dates are, of course, computed when the expansion takes place.