To me, it depends a lot on how the fight went i.e. if it did put the issues in the light in a way that the reader can see how that specific fight was necessary for the relationship to start back on healthier bases.
Take two pretty opposites scenarios:
1 - Their fight is about lauching at each other their dishonest behaviour, trying to escape responsibilities and/or put the responsibilities on the other: time skip to reconciliation would be a very bad idea, disappointing and in my opinion, a bit creepy (at least not announcing anything good for the future; for sure not a real happy ending). I know that's not what you want to do, but my first thought was, if you don't have time to explain how things got better, the logical thing to do would be to write a separation.
2 - Fighting is about putting everything on the table and discussing issues, why they happened, not refusing responsability. That can still be fighting, these scenes can be pretty intense, but be, in a way, constructive fighting. Then I could imagine a time skip COULD be ok, although not desirable (could be better if there is some appeasement or calmer/more introspective moments from both protagonists at the end of the fight.