How about a personalized book subscription? There are a few services that offer customized monthly book deliveries based on the recipient’s reading tastes. You could also consider getting him a special edition or signed copy of one of his favorite books, or a new book by one of his favorite authors. Another option could be to create a reading nook or cozy space for him to enjoy his books at home.
Or you can get him a star map with the date of your anniversary.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.