How many hours did they work in Buchenwald in Daniel's Story?

Buchenwald was a forced labor camp—as opposed to an extermination camp, like Auschwitz. This means that prisoners who passed through its gates were there primarily to work rather than to be executed. Of course, conditions were utterly appalling (with many prisoners worked to death), but the purpose of Buchenwald—forced labor—was different to that of Auschwitz: which was mass extermination.
As Daniel tells us, Buchenwald is full of factories, and the Jewish inmates are forced to work long and hard in them. Each working day lasts fourteen hours, with roll-calls every morning to ensure that none of the prisoners have escaped overnight. There is a truly horrible fate in store for anyone who makes the attempt, as Daniel sees for himself.
He witnesses the terrible punishment meted out to seven young Polish men caught trying to escape. They are tied down to their cots and fed nothing but salt water. They linger on in agony for three whole days until they eventually die. Buchenwald may not have the same purpose as Auschwitz, but it's no less of a monument to Nazi bestiality.