You can tell because every shadow will show the weird shape of the sun. Here is a photograph of the shadows during an annular eclipse: https://imgur.com/galler

You can tell because every shadow will show the weird shape of the sun. Here is a photograph of the shadows during an annular eclipse: https://imgur.com/gallery/8c7rdEU https://imgur.com/gallery/8c7rdEU Whether or not people >1000 years ago would notice this and record it... I refrain from pretending to know.