A “sabbatical” is supposed to be a time apart, a sacred time, a time of silence and waiting.  Translated from the Hebrew it might be ceasing or releasing.  It is, of course, based on God’s ceasing or resting on the 7th day after creation.  Its religious purpose varies according to different traditions, but rest is clearly one of them, as is release from burden (even beasts were not supposed to labor), and making holy those things that grow naturally (fruit that grows in the seventh year without cultivation is seen as holy in a special way).  All of these involve not just napping, but a considered attitude towards oneself, others, and the earth.