Persona 3 FES Request 99
This request is unique to Persona 3 FES and it requires you to collect Machine Oil from Aigis 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.
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!