Yes, the SAVEDATE field , including TIME IS checked...but it
does NOT update.
When you test this, are you making an actual change in the
document, like adding an extra space somewhere or inserting
another type of character? If (a) you have the SAVEDATE filed
inserted correctly, (b) you open the file and make a change, and
(c) save the file on a different date than the previous time you
saved it, then the date should be updated and when you open it
again it will reflect the last saved date. I'd guess that you are
not actually making any changes to the document, and, therefore,
it's not really being saved in a new state.