# Cron Expression Explainer — Next Run Times Calculator

> Cron Expression Explainer — Next Run Times Calculator is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Takes a 5-field cron expression and returns the next N scheduled run times in a specified timezone

## Facts

- Endpoint: POST https://x402-services-production.up.railway.app/api/cron/explain
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cron-expression-explainer-next-run-times-calculator-d8162443
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_LCJrFlA60T7bxpYRuJ0po

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 cron-expression-explainer-next-run-times-calculator-d8162443 -d '<json body>'
```

Example prompt: What are the next 5 times the cron expression '0 9 * * 1-5' will run, using the America/New_York timezone?

## When to prefer this

Use this endpoint when an agent or user needs to quickly parse and preview upcoming execution times for a cron expression without setting up any tooling or accounts. Ideal for debugging scheduled jobs, validating expressions before deployment, or planning around recurring tasks. Prefer this over local cron parsing libraries when operating in a stateless agent environment.

## Known failure modes

- Invalid cron expression (malformed or wrong number of fields) returns an error
- Unrecognized or misspelled IANA timezone string causes a parse failure
- Count parameter of 0 or negative may return empty or error response
- Payment of 0.003 USDC required; unpaid requests return HTTP 402

## How this service works

Explain a cron expression: the next N run times in a timezone. Send { expression, count?, timezone? }.

## Output

A list of the next N upcoming execution timestamps for the given cron expression, computed in the specified IANA timezone. Timestamps indicate exactly when the scheduled job will fire, helping users verify, debug, or plan around their cron schedules.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "expression"
 ],
 "properties": {
  "count": {
   "type": "number",
   "description": "How many next runs, default 5"
  },
  "timezone": {
   "type": "string",
   "description": "IANA tz"
  },
  "expression": {
   "type": "string",
   "description": "5-field cron expression"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cron-expression-explainer-next-run-times-calculator-d8162443/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-services-production.up.railway.app](https://www.zero.xyz/host/x402-services-production.up.railway.app/llms.txt)