A deity called Sabbath does not occur in the Bible. For the first time it seems to be found in Valentinian ‘mythology’. It is quite probable that the creation of a deity with this name was based on the interpretation of a NT passage (Luke 6.5).
Tertullian (Adv.Val. 20:1–2) describes the Valentinian view of creation: the Demiurge made this world and its hemisphere, then “completed the sevenfold stage of heavens, with his throne above it. That is why he is called Sabbatum, because of the hebdomad of his reside…