Calendar year ("leap days" or "intercalary days"). The Gregorian year, which is in use in most of the world, begins on January 1 and ends on December 31. It has a length of 365 days in an ordinary year, with 8,760 hours, 525,600 minutes, or 31,536,000 seconds; but 366 days in a leap year, with 8,784 hours, 527,040 minutes, or 31,622,400 seconds. With 97 leap years every 400 years, the year has an average length of 365.2425 days. Other formula-based calendars can have lengths which are further out of step with the solar cycle: for example, the Julian calendar has an average
Middle-earth calendar is year 1421 on the Shire calendar. A year in the Shire is the same length as our year – 365 days, 5 hours, 48 minutes, 46 seconds. The Shire's calendar year is also divided into 12 months but all of 30 days. Five additional days are added to create a 365-day year. For the names of the months, Tolkien used reconstructed names derived from the Anglo-Saxons; in other words, they are Tolkien's take on what English would be actually using now if it had not adopted Latin names for the months (January, February, March, etc.). The "Yuledays" are the