When people speak of the age of the universe they very rarely finish their sentences.
The universe is about 15 billion years old from our space/time coordinates and it is also about an equivalent 6 days old from the inception space/time coordinates.
This is due to the big bang and inflationary theory (relativity).
Some researchers (using other methods) extend it to 13.82 BY -- but that is still within the tolerances given above.
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But, from the inception space-time coordinates, (God's viewpoint) it is still