Stewards' Reckoning, also known as the Revised Calendar, was the calendar system introduced in Gondor by its first Ruling Steward, Mardil Voronwë, in Third Age 2060. It replaced the previous system known as the Kings' Reckoning and, following the War of the Ring, it was replaced by the New Reckoning.
Arnor and Gondor used a Númenórean calendar called the Kings' Reckoning. Even after the fall of Númenor near the end of the Second Age, the old calendar was maintained by the Exiles of Númenor in Middle-earth well into the Third Age. When the era of the Kings passed with the fall of Arnor and the loss of King Eärnur, the Kings' Reckoning presented (due to resetting the "millennial additions" with the new count of Third Age years) an offset of about 2 days out of synchronicity with the solar year.[note 1]
To correct the accumulating deficit of the calendar, Steward Mardil inserted two leap days into T.A. 2059. In addition, he reformed the calendar, to take effect in 2060, by making all months of equal length at 30 days and arranging the two extra days as holidays outside of the months. In 2360 Steward Hador added 1 day to that year. There were no millennial additions in 3000, but by the end of the Third Age the calendar was in deficit by less than 1 day.
The Stewards' Reckoning was eventually adopted by most speakers of Westron.
 The Calendar
The Revised Calendar consisted of twelve months, each of thirty days, and five additional days that belonged to no month. The months were taken from those of the Kings' Reckoning, with the change that the seventh and eighth months were shortened to thirty days, and the two days placed outside the months as tuilérë, meaning Spring-day, and yáviérë, meaning Autumn-day.
|Month number||Quenya||Sindarin||Length||Relationship to the Shire Calendar[note 2]|
|4||Víressë||Gwirith||30||2 Astron through 1 Thrimidge|
|5||Lótessë||Lothron||30||2 Thrimidge through 1 Forelithe|
|6||Nárië||Nórui||30||2 Forelithe through 1 Lithe|
|7||Cermië||Cerveth||30||2 Lithe through 29 Afterlithe|
|8||Úrimë||Urui||30||30 Afterlithe through 29 Wedmath|
|9||Yavannië||Ivanneth||30||30 Wedmath through 29 Halimath|
- Yestarë: approximately the Winter Solstice
- Tuilérë: near or just after the Vernal Equinox
- Loëndë: approximately the Summer Solstice
- Yáviérë: near or just before the Autumnal Equinox
Tolkien stated that the deficit remaining after Steward Mardil's 2-day addition to T.A. 2059 was "about 8 hours". The Lord of the Rings: A Reader's Companion states that the remaining deficit at the end of 2059 should have amounted to "2 hours, 16 minutes, 40 seconds".
Andreas Möhn goes further in his blog post "Tolkien has reckoned correct after all", speculating that Tolkien "failed to specify" additional Stewards' Reckoning rules, which would explain the deficit figures published in Appendix D.
Paul Sarando suggests instead that a simpler explanation for Tolkien's puzzling "about 8 hours" may have been the result of a mathematical shortcut of using the deficit calculation for the end of Second Age 5501 (which would have been the same year as T.A. 2060 if the count of Second Age years had continued) instead of correctly calculating the deficit for S.A. 3441 plus the end of T.A. 2060.
- ↑ The length of the solar year given in Appendix D was 365 days, 5 hours, 48 minutes, 46 seconds.
- ↑ Based on the statement in Appendix D that the day of the destruction of the One Ring, Shire 25 March in T.A. 3019, "was, however, March 25 in both Kings' and Stewards' Reckoning." This may only apply around the end of the Third Age, since it is unknown if the Shire Calendar incorporated the Kings' Reckoning 2-day "millennial additions" or any of the Stewards' Reckoning additional adjustments.
- ↑ 1.0 1.1 1.2 1.3 J.R.R. Tolkien, The Lord of the Rings, Appendix D, "The Calendars"
- ↑ 2.0 2.1 2.2 Wayne G. Hammond and Christina Scull, The Lord of the Rings: A Reader's Companion, "Appendix D", p. 729
- ↑ Aaron Chong, "Tolkien's Legendarium versus Astronomical Reality" dated 5 March 2016, Redirected Insanity (accessed 15 May 2018)
- ↑ Andreas Möhn, "The Reckoning of Time", Lalaith's Middle-earth Science Pages (accessed 30 April 2006)
- ↑ Andreas Möhn, "Tolkien has reckoned correct after all" dated 9 March 2018, Lalaith's Middle-earth Science Pages (accessed 15 May 2018)
- ↑ Paul Sarando, "The Kings’ Reckoning Rules and the Deficit", Shire Reckoning: A visualization of the calendars described in J.R.R. Tolkien's The Lord of the Rings Appendix D (accessed 15 May 2018)