Dateward

Today's date in seven systems at once — Gregorian, Julian, Hebrew, Islamic tabular, Persian, ISO week and Julian Day — and a converter that takes any date in any of them and gives the rest. Everything runs through the Julian Day Number, so every conversion can be shown step by step, and the weekday of any date is one division with the remainder on screen. Count the days, weeks, months and working days between two dates. Find the movable dates of any year: both Easters, Advent, Rosh Hashanah, the tabular start of Ramadan with a note about sighting, Nowruz. - 160 articles in seven chapters: counting days, the 1582 reform and who adopted it when, the Julian rule and its drift, the Hebrew 19-year cycle and its postponement rules, the Islamic 30-year cycle, the Persian equinox calendar, ISO weeks and the computus - Each article shows worked dates, the usual off-by-one, the years and regions the rule does not cover, and a date to check in the converter - Your own anniversaries, recalculated into every system with a count of days to go, exportable to a file - Results outside a calendar's valid range are explained in words, not shown as an error Religious calendars appear here as counting systems and nothing more; dates are given by rule, with no judgement attached. Runs without a connection and without an account; nothing is advertised, nothing is measured, nothing is sold and no permission is ever requested. Your marks stay on the device and can be saved to a file.