# Agent402 UK Cron Expression Validator & Next Fire Times

> Agent402 UK Cron Expression Validator & Next Fire Times is a paid API for AI agents from agent402.co.uk, paid per call via x402, $0.001/call, status down (last checked 2026-10-12).

Validates a cron expression and returns the next N scheduled fire times in a specified IANA timezone, optionally starting from a given ISO datetime.

## Facts

- Endpoint: POST https://agent402.co.uk/v1/time/cron?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-uk-cron-expression-validator-next-fire-times-9b968428
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0ZyAuxBK2eJaVnH54is6J

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 agent402-uk-cron-expression-validator-next-fire-times-9b968428 -d '<json body>'
```

Example prompt: Can you validate the cron expression '0 9 * * 1-5' and show me the next 5 fire times in Europe/London timezone, starting from 2026-08-11?

## When to prefer this

Use this endpoint when you need deterministic, IANA timezone-aware cron schedule validation and fire-time preview — particularly inside scheduler loops, deployment pipelines, or agent workflows that need to confirm schedule correctness before committing. Prefer this over client-side cron libraries when you need authoritative server-side validation with timezone normalization, or when the agent runtime lacks a reliable cron parser.

## Known failure modes

- Invalid cron expression returns valid:false with no fire times
- Count outside 1–50 range may return a validation error
- Unrecognized IANA timezone string causes an error
- Malformed ISO 'from' datetime causes a parse error
- Missing required 'expression' field returns an error response

## How this service works

Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.

## Output

Returns a JSON object containing: the origin datetime used ('from'), an array of next fire times as ISO strings ('next'), the requested count, a 'valid' boolean indicating whether the cron expression is syntactically correct, the resolved IANA timezone, the original expression, and a normalized form of the expression.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tz": {
   "type": "string",
   "description": "IANA timezone (default UTC)"
  },
  "from": {
   "type": "string",
   "description": "ISO origin for next fires (default now)"
  },
  "count": {
   "type": "number",
   "description": "How many next runs (1-50)"
  },
  "expression": {
   "type": "string",
   "description": "Cron expression (5 or 6 field)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "from": "2026-08-11T00:00:00.000Z",
  "next": [
   "2026-08-11T08:00:00.000Z",
   "2026-08-12T08:00:00.000Z"
  ],
  "count": 5,
  "valid": true,
  "timezone": "Europe/London",
  "expression": "0 9 * * 1-5",
  "normalized": "0 9 * * 1-5"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-uk-cron-expression-validator-next-fire-times-9b968428/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.co.uk](https://www.zero.xyz/host/agent402.co.uk/llms.txt)