The death anniversary of U Soso Tham is observed in Meghalaya, India, every December 18. This day commemorates the renowned poet who significantly contributed to the development of the Khasi language and literature. U Soso Tham, born in 1873, was the first to write secular poetry in Khasi and introduced Khasi idioms in a style influenced by English poetry. His notable works include "The Golden Harp," which features 46 original poems and 14 translations, and "The Olden Days of U Hynniew Trep," a long poem about the Hynniew Trep people. The observance is marked by flower-laying ceremonies at monuments dedicated to Tham, organized by the state government, educational institutions, and cultural organizations throughout Meghalaya. The day serves to honor his legacy and the importance of Khasi literature.