I have three subscriptions to RWM MACBA, http://rwm.macba.cat/api/en/all_podcast/79.xml, 80.xml and 86.xml. They all display the same behaviour, where new posts are assigned the epoch date, 1st January 1970, and the feeds are shown as last updated 48yrs ago. Looking at the xml, there are no obvious dates, so it may be a feed issue, rather than a product problem. feedly shows sane timestamps for new items, so they're extracting that data from somewhere.
If their feeds are to blame, what should they be including to make them standards-compliant, so you would display them correctly?
Thanks,
Jason