Time 'itself' cannot exist outside anything to mark it's existence. Since nothing but God existed, there was no time, obviously, from the text: "... the first day." Were time infinite, God would NEVER reach the first second of creation, since time goes back eternally.
Ps. 90:2 There is a moment before and after creation. Endless time (duration, sequence, succession) is fully consistent with Scripture, logic, science.
If we get rid of every time piece in the world, time still marches on because it is a concept of duration, not a thing like a rock or person. You can stare at a clock and measure time consciously. When you are sleeping or if the clock battery dies, succession still marches on.
God had triune, personal relations before material creation that involved succession in His being (think, act, feel successively like Scripture shows vs eternal now Platonic philosophy adopted by Augustine that you now uncritically embrace).
Rev. 1:4 show past, present, future (tensed vs timeless) in relation to God.
I AM means self-existent, not timeless.
Alpha and Omega is eternality, no beginning, no end, not timeless, no sequence.
Wrong assumptions lead to wrong conclusions.
Jesus experienced time fully as the God-Man. There is no problem for a personal being to experience duration. Timelessness is not found in Scripture nor is it logical, just pagan philosophical.
If you think time is a limitation for God like it is for us, you are wrong.
I do not see why you cling to a wrong idea when alternate ones are more evidence based. If you are not familiar with the academic debate about time, I would be slower to be so closed/dogmatic about your view.