From within, all you see is an impenetrable darkness. Access to magic is lost for arcane, divine, natural, and supernatural abilities. Dying creatures are automatically stabilized and any persistent damage effects cease. No food is required for sustenance, nor water, nor need for a restroom. The prisoner(s) is immune to harm of any sort (including aging.) A prisoner released will not retain any memories of being inside. For them, that time is lost.

Upon command the prison will absorb a single unwilling prisoner with a Wisdom save DC 17, or up to 5 willing prisoners. If the target has ever been imprisoned by a Prison of Lost Time rolls their saves at a disadvantage

In order to release a prisoner, the command word must be uttered from outside the cell. Each command will empty the cell if occupied, by default. A new prisoner may not be added to an occupied cell... even if they are willing and the cell is not at max capacity