I won't deny that, many animes/magnas are like that, but for Death March, many events happened in just a few day, for example, day 1 Satou arrives at Seiryu City, day 2 Satous goes on a date with Zena, then the labyrinth incident. I can't remember how many days Satou spent in the labyrinth, but it shouldn't be more than 2 days since people are still moving fine, all of that took 2 volumes, in other words, 2 volumes, and it hasn't even been a week has passed in the series, and many of the events after that too, even though it seems long but in reallity it goes on for just a few days