Thawathotsamat (Thai: ทวาทศมาส, pronounced [tʰā.wāː.tʰót.sā.mâːt]; lit. 'Twelve Months') is a poem of 1,042 lines in Thai, probably composed in the late fifteenth century CE. The title is a Thai adaptation of the Pali-Sanskrit words dvā dasa māsa, two ten months. The male speaker laments over a lost lover through the course of one year, drawing on the seasonal weather for similes of his emotions. Both the speaker and beloved are addressed with royal forms. A late verse declares that the poem was written by a "young-king" with the help of three court poets. The work has sometimes been mistakenly classified as a treatise on Siamese royal ceremonies. The work is less studied and less well-known than other early works of Thai literature, partly because of the obscurity of its archaic language, and partly because of conservative concerns over its erotic passages. A new annotated Thai edition appeared in 2017.