Taking the basic approach (sorry, I don't have the syntax in my memory, but
the strategy would be)...
You could create a table specifically to store this "audit" information;
with fields for the date/time, the form name, and possibly the user name.
The date/time could be acquired by setting the default value for the field
to Date().
You'll need VBA for this...
Every form has an OnOpen event. You could program that event to use a SQL
statement to write a record into the "audit" table.