Free Cron Expression Parser Online

Validate a cron expression and get its next run times in any timezone, with a plain-English description. Supports 5, 6 and 7-field cron syntax.

Result

Press “Run” to see the result.

The Cron API validates a cron expression and calculates when it will fire next. You get up to 100 upcoming runs (count, default 5), each as a UTC ISO timestamp and as local time in the timezone you choose (any IANA name such as Asia/Ho_Chi_Minh; default UTC), so daylight-saving changes are handled correctly.

Standard 5-field expressions (minute hour day month weekday) are supported, as well as 6 and 7-field variants with seconds and year, ranges, steps (*/15), lists and names. For 5-field expressions the response includes a short description such as "at 09:00, on weekdays". Use from (an ISO date) to compute runs after a given moment instead of now.

Invalid expressions do not raise an HTTP error: the API answers valid: false with the parser’s error message, which makes it easy to validate user input in a scheduling form.

Use this in your code

curl "https://apibox.io.vn/v1/cron?expression=0%209%20*%20*%201-5&timezone=Asia/Ho_Chi_Minh&count=3" \
  -H "Authorization: Bearer YOUR_API_KEY"

const res = await fetch('https://apibox.io.vn/v1/cron?expression=0%209%20*%20*%201-5&timezone=Asia/Ho_Chi_Minh&count=3', {
  method: 'GET',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
  },
});
const data = await res.json();
console.log(data);

import requests

res = requests.get(
    "https://apibox.io.vn/v1/cron?expression=0%209%20*%20*%201-5&timezone=Asia/Ho_Chi_Minh&count=3",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    timeout=30,
)
print(res.json())

<?php
$ch = curl_init('https://apibox.io.vn/v1/cron?expression=0%209%20*%20*%201-5&timezone=Asia/Ho_Chi_Minh&count=3');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY'],
]);
$response = curl_exec($ch);
print_r(json_decode($response, true));

API documentation → Get a free API key

FAQ

Which timezone are the next runs computed in?

In the timezone parameter (default UTC). Each run is returned both as a UTC timestamp and as local time in that zone, e.g. 0 9 * * 1-5 in Asia/Ho_Chi_Minh fires at 02:00 UTC.

Does it support seconds?

Yes. 6-field expressions start with a seconds field and 7-field ones end with a year. The English description is only produced for classic 5-field expressions.

What happens with an invalid expression?

You get HTTP 200 with valid: false and an error message explaining the problem, for example that five, six or seven space-separated parts are required.