12 Services from calendar-systems.x402tookit.com

Determines whether a given year is a leap year in the Gregorian, Julian, Hebrew, Islamic (tabular), or Persian calendar, and returns the applicable rule plus adjacent leap years.

Returns moon phase name, age in days, illumination fraction, and previous/next lunar event times (new moon, quarters, full moon) for a given date.

Returns the Chinese zodiac animal, element, yin/yang polarity, sexagenary cycle info, and Chinese New Year date for a given Gregorian year or date (table coverage 1901–2100).

Convert a Gregorian date to the Hebrew calendar (or vice versa), returning the Hebrew date, month name, year type, leap year status, and major holidays for that Hebrew year.

Converts a Gregorian or Julian calendar date and UTC time to Julian Day (JD), Modified Julian Day (MJD), and Julian Day Number (JDN), or converts a JD number back to a calendar date.

Returns the exact UTC moments of the March equinox, June solstice, September equinox, and December solstice for any Gregorian year from 1900 to 2100, along with season lengths in days.

Converts a Gregorian date to the Islamic tabular civil calendar date (or vice versa), returning month name, leap year status, observances, and a disclaimer that this is a calculated approximation, not based on moon sighting.

Returns the weekday, day of year, quarter, ISO week, and ISO week-date for any date from year 1 to 9999, supporting both Gregorian and Julian calendars.

Converts a date between the Gregorian (New Style) and Julian (Old Style) calendar systems, returning both dates and the day difference between them.

Converts a Gregorian date to the Persian Solar Hijri calendar (or vice versa) using the astronomical Nowruz rule, covering years 1901–2100.

Returns all lunar phase events (new moon, first quarter, full moon, last quarter) for a given month in UTC, with exact times and a blue-moon flag.

Returns a comprehensive age profile for a birth date including years/months/days lived, Korean/East Asian ages, next birthday with leap-day handling, and Chinese zodiac.