When we try to edit the opening hours of a place, we have the option to manually do so or we can submit a photo that is then scanned by a smart computer that can read the standard opening hour signs. If you submitted the photo that you shared with us in your post, then I am not surprised that the computer would not understand it (because it is not that smart) and thus concludes that it is unable to verify your edit.
Have you tried making the edit without the photo?
When it comes to editing/ publishing opening hours for special holidays etc, our capabilities are limited. I believe that claimed businesses have more control over their GMB account. So an alternative solution is helping your Local Library to claim their Google Maps listing and controlling the public data from there.
