# Age on Date Calculator

> Age on Date Calculator is a paid API for AI agents from x402-zoo.lolagent.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Calculates the completed age in years of a person on a specified date given their ISO birth date.

## Facts

- Endpoint: GET https://x402-zoo.lolagent.workers.dev/api/age-on-date
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/age-on-date-calculator-eb3f6acb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lhV0gjBf-ekGxYgZjCmtR

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 age-on-date-calculator-eb3f6acb
```

Example prompt: How old will someone born on 1990-03-15 be on 2025-07-04? Give me their completed age in years.

## When to prefer this

Use this endpoint when you need a precise, deterministic calculation of someone's completed age in whole years on any past, present, or future date — especially in legal, healthcare, eligibility-checking, or event-planning contexts where correct age calculation matters. Prefer it over manual arithmetic or general-purpose LLM reasoning to avoid off-by-one errors around birthdays.

## Known failure modes

- Missing 'birth' query parameter returns an error
- Invalid ISO date format for birth or target date causes a parsing error
- Future birth dates or dates before epoch may return unexpected results
- If 'on' date is omitted the endpoint may default to today or error
- Network or worker timeout on edge infrastructure

## How this service works

Calculate age in completed years on a specified date from an ISO birth date.

## Output

Returns the number of completed (whole) years of age the person has reached by the specified date, calculated from the provided ISO birth date.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "birth"
     ],
     "properties": {
      "on": {
       "type": "string"
      },
      "birth": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/age-on-date-calculator-eb3f6acb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-zoo.lolagent.workers.dev](https://www.zero.xyz/host/x402-zoo.lolagent.workers.dev/llms.txt)