When you say "semantically maps" do you mean that somebody somewhere coded such a "fact" into the training set? Or how is the mapping specified? If the training texts say "Current year is 2023" it would be wrong already :-)
So even though a training resource said "It is DATE today. An IMPORTANT THING happened.", it knows that IMPORTANT THING happened in the past, because it knows CURRENT DATE from the system prompt, and it also knows that DATE < CURRENT DATE.
I didn't know about "system prompts".