Proleptic Julian calendar with year 0 corresponding to 1 BC, and "year −1" corresponding to 2 BC, so that in this system, Julian leap years have a number divisible by four. The determination of leap years in the proleptic Julian calendar (in either numbering) is distinct from the question of which years were historically considered leap years during the Roman era, due to the leap year error: Between 45 BC and AD 4, the leap day was somewhat unsystematic. Thus there is no simple way to find an equivalent in the proleptic Julian calendar of a date quoted using the Roman pre-Julian calendar
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