There have been no confirmed updates or data refreshes for both the Panda and Penguin algorithms since 2014. Yesterday in a Google Hangout, it was addressed that the algorithms are not updating regularly, and that someone at Google has to push them out manually.
Google’s John Mueller said, “I think both of those algorithms [Panda and Penguin] currently are not updating the data regularly. So that is something for both of them, where we kind of have to push the updates as well.”
Going back, the Panda 4.1 was probably the last Panda update and it was tweaked and rolled out over in several weeks with the last one being around October 24th, 2014. With Penguin, there have been no updates since December 6th, 2014.
Those sites impacted negatively by either of the algorithms want a refresh to see if they have recovered. Without a data refresh, their sites cannot recover from the algorithm. Of course they may see small increases or fluctuations in their rankings due to other Google algorithms but they won’t see a full recovery until the algorithm is refreshed.