You once said that players only have 24 hours to beat the game, but wasn't it mentioned in comic that it took the trolls several months before they won?

Players have 24 hours to beat the Black King once he starts the Reckoning.

As far as I’m aware, the average amount of time before he starts the Reckoning is usually a few weeks like Karkat’s group had, although it might differ by session.

The Beta kids’ Reckoning started super early (Less than a day in) due to interference by Bec Noir.