God is not restricted to our timeline.

But, beloved, do not forget this one thing, that with the Lord one day is as a thousand years, and a thousand years as one day. -- 2 Peter 3:8 (NKJV)

For a thousand years in Your sight are like yesterday when it is past -- Psalm 90:4 (NKJV)

Therefore, God is called:

• "The Alpha and Omega" / "Aleph-Tav"? (Revelation 1:8, 21:6, 22:12)
• The "First and the Last" (Isaiah 41:4, 44:6, 48:12, Revelation 1:8, 21:5-8, 22:13)
• "beginning and end" (Isaiah 41:4, 48:2-3, 48:12; Revelation 1:8, 21:6, 22:12)

Example where God's past is our future

Sometimes prophecies would refer to our future as God's past.

Your eyes saw my substance, being yet unformed. And in Your book they all were written, The days fashioned for me, When as yet there were none of them.

-- Psalm 139:16 (NKJV)

Remember the former things of old, For I am God, and there is no other; I am God, and there is none like Me, Declaring the end from the beginning, And from ancient times things that are not yet done,

-- Isaiah 46:9-10 (NKJV)

“Before I formed you in the womb I knew you;
Before you were born I sanctified you;
I ordained you a prophet to the nations.”

-- Jeremiah 1:5 (NKJV)

Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love.

-- Ephesians 1:3-4 (NKJV)