
War of Wrath
The First Age ends with Morgoth’s defeat and the loss of Beleriand.
Sources: J. R. R. Tolkien, The Return of the King, Appendix D “Calendars”. London: George Allen & Unwin, 1955.

The Lord of the Rings
In Appendix D of The Lord of the Rings, Tolkien describes the Shire Reckoning: every month has 30 days, and a few extra days sit between the months.
Selected historical date
First Age
From the work

The First Age ends with Morgoth’s defeat and the loss of Beleriand.
Sources: J. R. R. Tolkien, The Return of the King, Appendix D “Calendars”. London: George Allen & Unwin, 1955.
Shire date
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Hypothetical Gregorian → Shire conversion; no canonical present-day Middle-earth year.
The Shire calendar has twelve 30-day months, two Yule days and three Lithe days. Leap years add Overlithe. Mid-year’s Day and Overlithe are outside the weekly cycle.
To link the Shire calendar to ours, this site assumes that 2 Yule falls on 22 December of the previous Gregorian year, so Mid-year's Day lands close to the summer solstice, and that Overlithe occurs in Gregorian leap years. This anchoring is our convention.
Historical dates are not synchronized with today. Artwork is illustrative.