Expire cache at a certain time?

Is it possible to have the cache for a certain page expire at a
certain time?


I have a page that pulls data from an external RSS feed that is
updated every Monday. I’d like the page to clear the cache on Monday
morning only so that it displays the most current results. Currently
I have my cache expiry set to 30 days.


One fast and effective solution is to have a periodic external process
the cache cleaning. On unix systems a simple ‘find’ command launched by
‘cron’ does the job.