Remember when we spoke of how they were not teaching cursive anymore because if you can read cursive you can read historical documents?
Try and find vampires weakness to sunlight in any stories from ancient "folk lore" Legends and myths of the blood drinking dead go back millennia, but search in vain for any hint that sunlight will do them any harm at all. Not the lamia, the lilitu, the weng chiang, upir, vyrvolokas or langsuir–not one vampire in folklore suffers from this weakness. Yet of all the ways to destroy the vampire, including burning or beheading or driving a nail/stake through the forehead/heart of the creature, look for any recommendation that sunlight will do the trick. You won’t find it anywhere.