It's possible to model by annotating facts in the database with a timestamp (Wikidata has this, as well as qualifiers for e.g. the source of a statement, or that it applies within a restricted context) but you still need to somehow integrate the information if you want to know the state right now. E.g. if you have (Jenny, date, Tom) from a year ago and (Jenny, date, Mike) from yesterday, does that mean (Jenny, date, Tom) is no longer valid? Or are both simultaneously true? Or is (Jenny, date, Mike) invalid too, because yesterday was like ages ago?

You could have some heuristics to handle this and then you add another relation "has met" and suddenly you need a whole new set of heuristics.