“How old is God? One popular answer is to say that God is infinitely old. However that is incorrect. God does not have an age as such, not even an infinite age. What time is it for God? There are 24 time zones in the world. Which one does He dwell in? To specify an exact time is to misunderstand what God is like. An atheist, no doubt, would exploit such conundrums about God and time and assert that God cannot exist. Some believers might dismiss such questions as esoteric or trite. However, God’s relationship to time is an important theological issue that Christians have wrestled with since the days of the early church.”
Read this helpful article here: The Trinity Foundation – The Omnitemporality of God.