In Josefine, Kafka interprets the generations’ temporality and the dominant way of being, and, what does it means to be:

“Among our people there is no age of youth, scarcely the briefest childhood. Regularly, it is true, demands are put forward that the children should be granted a special freedom, a special protection, that their right to be a little carefree, to have a little senseless giddiness, a little play, that this right should be respected and the exercise of it encouraged; such demands are put forward and nearly everyone approves them, there is nothing one could approve more, but there is also nothing, in the reality of our daily life, that is less likely to be granted, one approves these demands, one makes attempts to meet them, but soon all the old ways are back again. Our life happens to be such that a child, as soon as it can run about a little and a little distinguish one thing from another, must look after itself just like an adult; the areas on which, for economic reasons, we have to live in dispersion are too wide, our enemies too numerous, the dangers lying everywhere in wait for us too incalculable— — we cannot shelter our children from the struggle for existence, if we did so, it would bring them to an early grave. These depressing considerations are reinforced by another, which is not depressing: the fertility of our race. One generation— — and each is numerous— — treads on the heels of another, the children have no time to be children. Other races may foster their children carefully, schools may be erected for their little ones, out of these schools the children may come pouring daily, the future of the race, yet among them it is always the same children that come out day after day for a long time.” —Franz Kafka, Josefine, the Singer,  or The Mouse Folk, 1924.

Could it be possible Kafka was reading Heidegger or vice-versa? The re-search continues: the book is here and the story, here.