I haven't used glossary, but poking around the code shows these lines in glossary-oracle/postgresql.tcl:
and publish_date > sysdate -1 (oracle)
and publish_date > current_timestamp - interval '1 day' (pg)
Perhaps changing it to:
and publish_date < sysdate (oracle)
and publish_date < current_timestamp (pg)
or maybe removing the clauses altogether will achieve the desired effect.
Please take this with a grain of salt, as I haven't used the module yet. =)