Oil based polyurethane

Hello! Just finished staining some 2x10s that we will be hanging over my desk to serve as a shelf for my 'fancier' books. Planning to seal them with an oil based polyurethane (Varathane) once the stain has cured.

How long should I wait before adding my book collection to the shelves once they're hung? I've been googling and it says anything from 3 days to a month for the oil base to properly cure. 🥴 Really don't want to ruin the books as some have been passed down for years.