The fact that one can have a memory belief about the future (or at least about the present) might be easier to see once another distinction has been made. I have a memory belief that the Japanese attacked Pearl Harbor on December 7th 1941, but there is a perfectly straightforward sense of ‘remember’ in which I can't be said to remember the attack.  Some philosophers want to make this distinction by saying that although I can remember that Pearl Harbor was attacked on that date, I can't remember the event itself.  To have the relevant sort of memory of the event (as opposed to only remembering a proposition about the event), I have to have experienced it myself.  Exactly what the “experience” requirement comes to is not entirely clear.  Although no one born after the event can truly be said to remember it in this sense, it isn't obvious that one had to be at Pearl Harbor on that date to have this kind of memory.  Hearing about it on the radio that evening is arguably sufficient for having remembering the event. Let's mark the distinction of this paragraph by calling the former ‘propositional memory’ and the latter ‘event memory.’ The objects of propositional memory are propositions; the objects of event memory are events.  My memory that the cake at the party was chocolate is propositional; my memory of the party is an event memory. While one can't have event memory of a future event, one might have propositional memory of a proposition that refers to an event that has yet to happen; one can remember that an event will take place.