Access does not store automatically the last time an edit to the data was made.
Your first task is to determine exactly what the request is.
In order from least complex to most complex
You could have a table with one field that gets constantly updated and would
show the last time any field in the entire database was updated.
Or you could have a field in each record that would show the last time each
record was updated.
Or you could track each change to the data in an audit table and have the last
time each field was updated or populated. Check the following out to get an
idea of how you might do this:
Audit Trail - Log changes at the record level at:
http://allenbrowne.com/AppAudit.html
You would have to do all data entry through a form in order to do this.
Unless you are using MS SQL Server or one of the other data base servers that
has triggers (or the equivalent) as the data store.
John Spencer
Access MVP 2002-2005, 2007-2009
The Hilltop Institute
University of Maryland Baltimore County