"These last few days" is a more natural translation than "these recent days".
It rejected "the storm of these last days was absolutely frightening". Reported 17 June 2018.
Reported again November 22 2018
It has rejected "The storm of these last days was absolutely frightening", "The storm of these last days has been absolutely frightening" and "The storm of these past few days was absolutely frightening" on December 13th
Pretty sure they're all correct translations
I wrote "The tempest ... " and got it wrong. It isn't the first time this has happened. Duo doesn't seem to like tempest as a translation of tempête.
Maybe "tempest" only means orage whereas "storm" is any garden-variety tempête?
'Absolutely frightening' is wrong. An extreme adverb goes with extreme adjectives!!!
So what are you suggesting instead?
"Absolutely terrifying" sounds more natural to me, but it is not currently accepted.
The singular should also be accepted since ce dernier jour has the same pronunciation, I think.