Cron Expression

GET/v0/cron

Validates a cron expression (5 or 6 fields). When valid, returns a human-readable description, the next scheduled run time, and the next 3 upcoming executions (in UTC).

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Query Parameters

Parameter	Type	Required	Description
value	string	Yes	Cron expression with 5 fields (minute, hour, day-of-month, month, day-of-week) or 6 fields (with seconds). Supports standard syntax including ``, `/n`, `1-5`, `1,3,5`.

Example Requests

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.isvalid.dev/v0/cron?value=0 3 * * 1"

Response Fields

Field	Type	Description
valid	boolean	Whether the expression is a valid cron expression
expression	string	The normalised cron expression
fields	number	Number of fields (5 or 6)
hasSeconds	boolean	Whether the expression includes a seconds field
humanReadable	string \| null	Human-readable description (e.g. "Every Monday at 3:00 AM")
nextRun	string	Next scheduled execution in ISO 8601 UTC
nextRuns	string[]	Next 3 scheduled executions in ISO 8601 UTC

Example Response

{
  "valid": true,
  "expression": "0 3 * * 1",
  "fields": 5,
  "hasSeconds": false,
  "humanReadable": "At 03:00 AM, only on Monday",
  "nextRun": "2026-03-09T03:00:00.000Z",
  "nextRuns": [
    "2026-03-09T03:00:00.000Z",
    "2026-03-16T03:00:00.000Z",
    "2026-03-23T03:00:00.000Z"
  ]
}

Example Response — invalid

{
  "valid": false
}