The lunatic fringe of Christianity, claim that "God is outside time" - they have no idea what this means but it explains why "created in 6 days" really means "created in billions of years"
As a consequence, you would have to explain whether by "all day" you mean "God's day" or "our day".
A further difficulty arises when we consider heaven: are there days and nights in heaven? For there to be day and night, there would have to be a star around which the planet "Heaven" orbited (or as we say in Biblical terms, "The star, made of burning coal, which goes round Heaven.")
However, this, itself has difficulties: nowhere is it indicated that "Heaven" is on a planet, nor that God requires illumination -> after all, when he made the earth, etc, he must have started in the dark.
A lot of God's timeless time is taken up with answering, ignoring and postponing answers to prayers. If each person on earth gives one prayer a day, God has 1/7 billionth of a day
to grant, reject or postpone the prayer whilst all the time considering what the effect of any of these actions will be upon the future plan for Armageddon - one false move and He's screwed.
On the seventh day, he rests: I assume that this means that all prayers on Sundays are either backlogged or ignored - as an atheist, I like to think that, on Sundays, they are ignored however vital they may be.