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 our own (Gregorian). It has a week of seven days. The calendar year has 365 days (except in leap-years), and twelve months ("astar"): ten with 30 days and two with 31. Unlike the Gregorian calendar, the King's Reckoning has some days outside the months. These special monthless days, a feature borrowed from Elvish Calendars, were generally holidays. Two of these special days were the pair which book-ends the year; thus, in the King's Reckoning, the last month of the year is followed by "mettarë", the last day of the year; this is then followed "yestarë", New Year's Day, which is