I don't think Article II, Section 2 is clear here. But I highly doubt he'd be in office anymore once things "come to light"
Discussion
It seems inefficient for Biden to limit the pardon period to only January 1, 2014 through December 1, 2024.
If this blanke-pardon-strategy works, it would be cleaner to just say “before December 1, 2024” and allow it to cover all potential wrongdoing since birth.