# Cron Expression Parser & Next-Run Calculator

> Cron Expression Parser & Next-Run Calculator is a paid API for AI agents from toolbelt402.tpoborne.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Parses and validates a cron expression, returning the next N scheduled run times as ISO 8601 timestamps in any IANA timezone.

## Facts

- Endpoint: GET https://toolbelt402.tpoborne.workers.dev/cron/next
- 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/cron-expression-parser-next-run-calculator-2f58e791
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_v3fwv5_IcteboyxY_JfPA

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-parser-next-run-calculator-2f58e791
```

Example prompt: Can you parse my cron expression '0 9 * * 1-5' and show me the next 10 run times in America/New_York timezone?

## When to prefer this

Use this endpoint when you need to quickly validate or preview cron schedules without running a live cron daemon or installing a library. Ideal for agents automating DevOps workflows, checking job configurations, or building scheduling UIs where users need to confirm what times their cron expression will fire in a specific timezone.

## Known failure modes

- Invalid cron expression returns an error indicating the expression could not be parsed
- Unsupported or misspelled IANA timezone returns a timezone-not-found error
- Requesting more than 100 runs (max) returns a validation error
- Missing required 'expr' query parameter returns a 400 bad request
- Extremely sparse cron schedules (e.g. every Feb 30) may return zero or few results

## How this service works

Parse and validate a cron expression — returns the next N run times as ISO timestamps in any IANA timezone. Cron schedule checker.

## Output

Returns an array of the next N ISO 8601 timestamps representing when the cron expression will trigger, calculated in the specified IANA timezone. Includes validation feedback if the expression is malformed.

## 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": [
      "expr"
     ],
     "properties": {
      "n": {
       "type": "string",
       "description": "How many runs (default 5, max 100)"
      },
      "tz": {
       "type": "string",
       "description": "IANA timezone (default UTC)"
      },
      "expr": {
       "type": "string",
       "description": "Cron expression"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cron-expression-parser-next-run-calculator-2f58e791/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toolbelt402.tpoborne.workers.dev](https://www.zero.xyz/host/toolbelt402.tpoborne.workers.dev/llms.txt)