Where I live, the apartment owner is required to make a reasonable effort to re-rent the apartment as soon as possible. If they do re-rent it, then you only have to pay for the period of time during which it was vacant (rather than the full 60 days).

I don't know if other locales, or your locale, have similar requirements.

Of course, it may also be difficult to prove just how hard they really tried to re-rent the place.

Ideally, if you could find another renter that they would accept, that could start sooner than 60 days, that might reduce the amount you have to pay.