It is highly based on the Germanic calendar.
Year 1 of the Shire Calendar corresponded when the Shire was founded by the Bree Hobbits Marcho and Blanco in the year 1601 of the Third Age. Therefore, years of the Third Age can be converted to Shire-years by subtracting 1600.
The last year of the Third Age was year 1421 on the Shire calendar.
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.
|Month number||Name||Approximate relationship to Gregorian calendar|
|2 Yule||22nd of December|
|1||Afteryule||23rd of December to the 21st of January|
|2||Solmath||22nd of January to the 20th of February|
|3||Rethe||21st of February to the 22nd of March|
|4||Astron||23rd of March to 21st of April|
|5||Thrimidge||22nd of April to the 21st of May|
|6||Forelithe||22nd of May to the 20th of June|
|1 Lithe||21st of June|
|Mid-year's Day||22nd of June|
|2 Lithe||23rd of June|
|7||Afterlithe||24th of June to the 23rd of July|
|8||Wedmath||24th of July to the 22nd of August|
|9||Halimath||23rd of August to the 21st of September|
|10||Winterfilth||22nd of September to 21st of October|
|11||Blotmath||22nd of October to the 20th of November|
|12||Foreyule||21st of November to the 20th of 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 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, which Tolkien describes as being 10 days earlier than the middle day of our year. However, since then the summer solstice has shifted slightly so it falls on a different date now, rendering the difference between Mid-year's Day and the middle day of our year eleven days, instead of ten.
Days of the week
There were seven days in the Shire week. The first day of the week was called Sterday and the last day of the week was called Highday. 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||Relationship to Gregorian calendar|
|Sterday||Stars of Varda||Monday|
|Trewsday||Two Trees of Valinor||Thursday|
Highday was a holiday with evening feasts.
In The Hobbit and The Lord of the Rings, the names of months and days are given in modern equivalents. For instance, Afteryule is called January and Sterday is called Monday. Basis: A footnote in the Appendices says "I have...used Saturday and Sunday instead of Thursday and Friday."