The calendar featured 12 months, all 30 days long, plus 5 or 6 named days added to round out 365 days (or 366 for leap years). Two of the named days were Yuledays; one was the first day of the year and the other was the last day of the year. Between June and July were the Lithedays. In regular years (not leap years) there were three: 1 Lithe, Mid-year's Day, and 2 Lithe. In leap years (every fourth year except in the last year of a century) an extra Overlithe Day was added after Mid-year's Day. All of the named days were major holidays (and a reason for feasting) with Overlithe being a day of special merrymaking. The two Yuledays were actually a portion of Yuletide, which included the last three and first three days of each year.
When the Hobbits were still a wandering people, their calendaric unit was not a 'week', but a 'month', governed more or less by the Moon. In their old calendar, the new year began after harvest. This can be seen in the name of the month Winterfilth meaning "filling (of the year) before winter".
However, through contact with alien peoples (perhaps the Dúnedain of Arnor) they adopted the notion of weeks which formed the Shire Reckoning. It was based on the King's Reckoning but with several minor alterations to fit their customs.
One innovation introduced by the Shire-hobbits was the Shire-reform. In the time of Thain Isengrim II they arranged that Mid-year’s Day (and the Overlithe) would not have a weekday name, which stopped the shifting of weekday names in relation to dates. This change made the first day of the year always correspond to the first day of the week, and the last day of the year always correspond to the last day of the week. Over time, since the same date in any year had the same weekday name as in any other year, the Shire-folk ceased to record the weekday in letters and diaries. Since no month began on a Friday this arrangement also birthed a jesting idiom in the Shire: "On Friday the first" referred to a non-existent day or one on which impossible things would occur (the full expression was "on Friday the first of Summerfilth").
 Months of the year and special days
The Shire calendar's year was divided into 12 months of 30 days. Five additional days were added to create a 365-day year. The months followed the lunar cycle.
The twelve months of the Shire Calendar were: Afteryule, Solmath, Rethe, Astron, Thrimidge, Forelithe, Afterlithe, Wedmath, Halimath, Winterfilth, Blotmath, and Foreyule. Solmath was usually pronounced and sometimes written as Somath. Thrimidge was often written Thrimich and Blotmath was pronounced as Blodmath or Blommath.
In the table below, the Bree names are given in brackets where appropriate.
|Month number||Shire Name||Bree Name||Approximate relationship to Gregorian calendar|
|2 Yule||22nd of December|
|1||Afteryule||Frery||23rd December to 21st January|
|2||Solmath||Solmath||22nd January to 20th February|
|3||Rethe||Rethe||21st February to 22nd March|
|4||Astron||Chithing||23rd March to 21st of April|
|5||Thrimidge||Thrimidge||22nd April to 21st May|
|6||Forelithe||Lithe||22nd May to 20th June|
|1 Lithe||The Summerdays||21st June|
|Mid-year's Day||22nd June|
|2 Lithe||23rd June|
|7||Afterlithe||Mede||24th June to 23rd July|
|8||Wedmath||Wedmath||24th July to 22nd August|
|9||Halimath||Harvestmath||23rd August to 21st September|
|10||Winterfilth||Wintring||22nd September to 21st October|
|11||Blotmath||Blooting||22nd October to 20th November|
|12||Foreyule||Yulemath||21st November to 20th December|
|1 Yule||21st of December|
The Yuledays were the days that mark the end of an old year and the beginning of a new one, so 2 Yule was the first day of the year. The Lithedays (referred to as the Summerdays in Bree) are the three days in the middle of the year, 1 Lithe, Mid-year's Day, and 2 Lithe. In leap years (every fourth year except centennial years) a day was added after Mid-year's Day called Overlithe. All these days were placed outside of any month. These days were primarily holidays and feast days. Mid-year's Day is meant to correspond to the summer solstice, being approximately 10 days earlier than the middle day of our year.
 Days of the week
The seven weekdays of the Shire Calendar (at the time of the War of the Ring) were Sterday, Sunday, Monday, Trewsday, Hevensday (or Hensday), Mersday, and Highday. The last day of the week, Highday, was the chief day, a post-noon holiday and time for evening feasts.
The Mid-year's Day and, when present, Overlithe had no weekday assignments. This arrangement was used because it caused every day to have the same weekday designation from year to year (instead of changing as in the Gregorian calendar).
|Day Name||Meaning||Translation in The Lord of the Rings||Relationship to Gregorian calendar|
|Sterday||Stars of Varda||Saturday||Monday|
|Trewsday||Two Trees of Valinor||Tuesday||Thursday|
Highday was a holiday with evening feasts.
It is highly based on the Germanic calendar.
Also, all days (except in Bilbo's Song) are translated according to the meaning of Sunday and Monday rather than according to position in the Gregorian calendar.
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix D
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix D, "The Calendars"
- The Shire-reckoning website, dedicated to detailed analysis of the Hobbit Calendar.