# Easter Date Calculator (Gregorian Algorithm)

> Easter Date Calculator (Gregorian Algorithm) is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Computes Easter Sunday and related Christian holidays (Good Friday, Ash Wednesday, Palm Sunday, Pentecost) for any given Gregorian calendar year using the Meeus/Jones/Butcher algorithm.

## Facts

- Endpoint: POST https://agent402.tools/api/easter-date
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/easter-date-calculator-gregorian-algorithm-d0e47e4b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IbLFj1M5jdBLqFFRy6jEI

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability easter-date-calculator-gregorian-algorithm-d0e47e4b -d '<json body>'
```

Example prompt: What are all the Easter-related holiday dates for 2026 — Easter Sunday, Good Friday, Ash Wednesday, Palm Sunday, and Pentecost?

## When to prefer this

Choose this endpoint when you need to programmatically determine the date of Easter or any of the associated movable Christian feasts (Good Friday, Ash Wednesday, Palm Sunday, Pentecost) for any year in the Gregorian calendar range 1583-9999. It is ideal for calendar applications, liturgical planning tools, or any workflow requiring accurate computation of Easter-related dates without building the algorithm locally.

## Known failure modes

- Year outside supported range (1583-9999) results in an error response
- Non-integer or missing year field causes a validation error
- Year in the Julian calendar era (pre-1583) is not supported

## How this service works

Compute the date of Easter Sunday for a given year using the Anonymous Gregorian algorithm (Meeus/Jones/Butcher). Also returns Good Friday, Ash Wednesday, Palm Sunday, Pentecost, and the day-of-year for Easter.

## Output

Returns the computed dates for Easter Sunday, Good Friday, Ash Wednesday, Palm Sunday, and Pentecost for the given year, along with Easter's day-of-year number, all derived using the Anonymous Gregorian (Meeus/Jones/Butcher) algorithm.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "year": {
   "type": "integer",
   "description": "Year (1583-9999, Gregorian calendar)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "year": 2026,
  "easter": "2026-04-05",
  "dayOfYear": 95,
  "pentecost": "2026-05-24",
  "goodFriday": "2026-04-03",
  "palmSunday": "2026-03-29",
  "ashWednesday": "2026-02-18"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/easter-date-calculator-gregorian-algorithm-d0e47e4b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)