The date this entry was last updated, as a string in the same format as it was published in the original feed).
As of version 5.1.1, if this key doesn’t exist but entries[i].published does, the value of entries[i].published will be returned.
In the past the RSS pubDate element was stored in updated, but this incorrect behavior was reported in issue 310. However, developers may have come to rely on this incorrect behavior – as was reported in issue 328 – so to help avoid hurting their users’ experience, this mapping from updated to published was temporarily introduced to give developers time to update their software, and to give users time to upgrade.
This mapping is temporary and will be removed in a future version of feedparser.