God does not exist in time. God transcends it.
According to Christian theology we as human beings live in what’s referred to as the “temporal realm” of existence. The theology teaches that change occurs on this plane of existence as we are bound by the dimensions of that in which we live. It also teaches, like science, that while always existent time is also relative.
This same theology teaches that God lives in a transcendent realm, called “eternity.” God is not bound by it since it is defined by God’s very existence. There is no space, no place, no time, no change. Future, present, and past are all one in that God transcends these very things.
This is another “Watchtowerism,” the teaching that God is also bound and tied up with time the way that Adventists are obsessed with it. It is has never been a teaching of Judaism or Christianity. The Christological view of existence on both planes is based on the ancient Hebrew.
This is why Scripture teaches that one day to YHWH is like a thousand years and also that while the heavens and earth will grow old, God will be able to ‘roll them up’ like one does with a garment for storage because God never changes.
This is also where the Watchtower teachings on heaven, hell, purgatory, paradise and other eschatological teachings fail because JW theology makes God subject to time and experience it as do humans. Even the JW view of celebrating Communion is warped due to this misunderstanding, leading to their one year and symbolism views.
Thus God never has had to contemplate eternity and being alone always in it. There is not past, present, or future for God. God himself Is, the very definition of Existence, of I AM. That is all defined by God.