From Tolkien Gateway

Cermië (Cerveth in Sindarin) was the seventh month of the year in the King's Reckoning and the Stewards' Reckoning of Gondor, following Loëndë, and preceding Úrimë. In the New Reckoning it was the fourth month of the year, immediately following Nárië.

Cermië in the Kings' Reckoning and in the Stewards' Reckoning corresponded, for the most part, to Afterlithe in the Shire Calendar (approximately modern 24 June through 23 July).[1]