Determination of the day of the week not a Gregorian leap year, (but 19 in the Julian column indicates that it "is" a Julian leap year, as are all Julian "x"00 years). 20 indicates that 2000 is a leap year. Use Jan and Feb only in leap years. For determination of the day of the week (1 January 2000, Saturday) For determination of the dominical letter (2000, BA) For determination of the doomsday (2000, Tuesday) Note that the date (and hence the day of the week) in the Revised Julian and Gregorian calendars is the same from 14 October 1923 to 28 February AD 2800 inclusive and
Names of the days of the week Sun and Moon ("sunnudagur" and "mánudagur" respectively), while dispensing with the names of the explicitly heathen gods in favour of a combination of numbered days and days whose names are linked to pious or domestic routine ("föstudagur", "Fasting Day" and "laugardagur", "Washing Day"). The "washing day" is also used in other North Germanic languages, but otherwise the names correspond to those of English. The ISO prescribes Monday as the first day of the week with ISO-8601 for software date formats. The Slavic, Baltic and Uralic languages (except Finnish and partially Estonian) adopted numbering but took Monday rather than Sunday as