Hi Maujb
One way this can be accomplished is by using a standalone script as a cron. On the server, the script should be setup as a scheduled task to run at given intervals. It would then check for current and expired records and publish or un-publish them based on the server-time.
Read this link to understand how to connect to your component from an external script:
Connecting to J-Cook from external Scripts / Crons
Your hosting provider should have the info you will need to schedule a task on their server.
Let me know if this helps.
Regards
v