Easter Date API
Easter Date API provides a simple, free endpoint for calculating the date of Easter Sunday for any given year, supporting both the Western (Gregorian) Easter calculation used by Roman Catholic and Protestant churches and the Eastern (Julian) Easter calculation used by Eastern Orthodox churches. Easter is a moveable feast that falls on a different date each year based on a calculation involving the spring equinox and lunar calendar, making programmatic calculation a practical need for app developers building religious calendar apps, church management systems, or any calendar application that needs to account for Easter-dependent holidays.
The Western Easter algorithm implemented by this API follows the calculation defined by the Gregorian calendar reform, producing the date on which Easter falls for Catholic and Protestant denominations — the Sunday after the first full moon on or after the vernal equinox (March 21). For Nigerian Christian app developers building church management software or religious calendar apps for Catholic, Anglican, Baptist, Methodist, Assemblies of God, or other mainstream Christian denominations (which together constitute the majority of Nigeria's southern Christian population), the Western Easter date is the relevant calculation.
Easter-derived dates are also computable once the Easter date is known: Ash Wednesday falls 46 days before Easter; Palm Sunday is the Sunday before Easter (6 days prior); Holy Thursday (Maundy Thursday) is 3 days before Easter; Good Friday is 2 days before Easter; and Pentecost Sunday falls 49 days after Easter. Nigerian church calendar apps that need to display the full Holy Week schedule and the date of Pentecost each year can calculate all these dates programmatically starting from the Easter date returned by this API.
Public holiday calculation in Nigeria includes Easter-adjacent days. Good Friday is a public holiday in Nigeria, as is Easter Monday. App developers building Nigerian public holiday calendars, HR management systems, or payroll applications that need to account for Easter-linked holidays can use this API to dynamically determine Good Friday and Easter Monday dates rather than hardcoding them. This is particularly useful for multi-year payroll or scheduling systems that need accurate holiday dates years in advance.
Eastern Orthodox Easter (Pascha) calculation is also supported, returning the Easter date according to the Julian calendar calculation used by the Greek Orthodox, Russian Orthodox, Serbian Orthodox, Romanian Orthodox, and other Eastern churches. While the Eastern Orthodox community is small in Nigeria, international businesses operating in Nigeria with Orthodox staff, or Nigerian-diaspora-focused apps, may require this calculation.
The API accepts a year as a query parameter and returns the Easter date in standard ISO 8601 format, making integration straightforward in any programming language or framework. Nigerian developers using JavaScript, Python, PHP, or any other common language can integrate the Easter Date API in minutes. The endpoint is free with no authentication required, no rate limits documented, and returns a simple JSON response with the calculated date, making it one of the simplest religious calendar APIs available for Nigerian Christian app development projects. School management systems in Nigerian private Christian schools can use the Easter Date API to automatically populate the school calendar with holiday dates each academic year — removing the risk of a school secretary miscalculating Easter and scheduling classes on Good Friday. Payroll software vendors serving Nigerian companies can integrate this API to dynamically compute Easter-linked public holidays for each year when processing payroll calendars. The API response is minimal and fast, returning only the computed date in a clean JSON structure, making it one of the most lightweight religious calendar API integrations available to Nigerian developers building feature-rich but performant applications.