# SiteCheck Cron Expression Parser

> SiteCheck Cron Expression Parser is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-27).

Parses a cron expression and returns the next N scheduled run times with human-readable explanations, optionally localized to a given timezone.

## Facts

- Endpoint: GET https://api.sitecheck-api.workers.dev/api/cron?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-cron-expression-parser-cea07a3e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mxeSZj-GHi5CQR0Fuqs9v

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 sitecheck-cron-expression-parser-cea07a3e
```

Example prompt: Can you parse the cron expression '*/15 9-17 * * 1-5' and show me the next 5 run times in the Europe/Berlin timezone so I know exactly when it will fire?

## When to prefer this

Choose this endpoint when you need to quickly compute and preview upcoming cron job fire times without setting up a local cron library. Ideal for DevOps agents validating deployment schedules, automation builders previewing task cadences, or any workflow that needs a human-readable explanation of a cron expression in a specific timezone — all with a single cheap API call at $0.001.

## Known failure modes

- Invalid or malformed cron expression returns an error
- count outside 1-20 range may be rejected or clamped
- Unrecognized IANA timezone string causes a timezone resolution error
- 6-field cron expressions may not be supported by all parsers — behavior may vary

## How this service works

Explains a cron expression in plain English and lists its next runs in UTC and in a time zone. Five fields (minute hour day month weekday), or six with seconds first. Names (MON, JAN) and steps are supported. Computed in the Worker; no network call.

## Output

Returns a JSON object with: a plain-English explanation of the cron expression, an array of next run times in local time with UTC offset, the corresponding UTC timestamps, the timezone used, and a checkedAt ISO timestamp. Computed entirely server-side with no external network calls.

## 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": [
      "expression"
     ],
     "properties": {
      "tz": {
       "type": "string",
       "description": "IANA time zone for the local times, e.g. Europe/Berlin (default UTC)"
      },
      "count": {
       "type": "string",
       "description": "Next runs, 1 to 20 (default 5)"
      },
      "expression": {
       "type": "string",
       "description": "Cron expression, 5 or 6 fields"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "source": "built-in cron parser (no network)",
  "nextRuns": [
   {
    "local": "2026-10-14 09:15:00",
    "utcOffset": "+02:00"
   },
   {
    "local": "2026-10-14 09:30:00",
    "utcOffset": "+02:00"
   },
   {
    "local": "2026-10-14 09:45:00",
    "utcOffset": "+02:00"
   }
  ],
  "timezone": "Europe/Berlin",
  "checkedAt": "2026-10-14T07:00:59.160Z",
  "expression": "*/15 9-17 * * 1-5",
  "explanation": "Every 15 minutes, from 09:00 to 17:59, on Monday to Friday",
  "nextRunsUtc": [
   "2026-10-14T07:15:00.000Z",
   "2026-10-14T07:30:00.000Z",
   "2026-10-14T07:45:00.000Z"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-cron-expression-parser-cea07a3e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)