Persona 3 FES Request 81
This request is unique to Persona 3 FES and it requires you to collect Gourmet Dog Food from Koromaru on this specific date. There are a few more requests like this one in the game all of them require you to speak with a specific member of SEES on a specific day and retrieve an item. These requests start at #92 and continue to #99. There are two though that don't fall into that number bracket, this being one of them.
None of the requests are required for you to do (nor do any of them flag you for a future request). Keep in mind that these quests do have a deadline so remember to return to Elizabeth shortly after completing it! Something I would like to mention for this request in particular as well is Elizabeth has quite the comical dialogue lines when you return to her with the Dog Food. If you normally skip through all the talking it's worth actually reading this one.