Since January 1st, the home page of fr.wiktionary.org contains new highlighted words each day. As a consequence, at midnight, the home-page of the (new) day becomes different from the one of the day-before. For users connected with their Wikimedia account, there is no problem. However, for non-connected users, there is a small "bug" : they receive the home-page of the-day-before instead of the home-page of the-day. I suspect that this is due to a cache, which has cached the home-page of the-day-before and which serves this "old" page instead of the current page to non-connected users. For connected-users, it is likley that the error deos not happen because each home-page delivered to them is dynamic (ie: having a slightly different content for each connected users (due to a different username included in the home-page).