Cron Expression Parser
Paste any cron expression and get a plain-English explanation plus the next 5 scheduled run times. Supports standard 5-field cron and 6-field (with seconds) syntax. Everything runs in your browser.
Developer Tools
What This Tool Does
Parses any cron expression into a plain-English description and shows the next 10 scheduled run times, entirely in your browser. Supports standard 5-field and extended 6-field (with seconds) cron syntax.
Who This Is For
- DevOps and platform engineers verifying that a cron schedule fires when intended
- Backend developers configuring scheduled tasks in CI/CD pipelines or cloud schedulers
- Anyone setting up cron jobs who wants to confirm the expression before deploying
- New engineers learning cron syntax by seeing human-readable translations immediately
Example: Input: A cron expression like 0 9 * * 1-5 → Output: "Every weekday at 9:00 AM" plus the next 10 run dates and times listed explicitly
How to Read a Cron Expression
A cron expression is a string of 5 or 6 fields that define a schedule. Cron exp claims appear in JWT tokens as Unix timestamps — the Timestamp Converter decodes them to readable dates. Each field specifies when a job runs along one dimension of time:
| Field | Position | Allowed Values | Special Characters |
|---|---|---|---|
| Minute | 1 | 0–59 | * , - / |
| Hour | 2 | 0–23 | * , - / |
| Day of Month | 3 | 1–31 | * , - / ? L W |
| Month | 4 | 1–12 or JAN–DEC | * , - / |
| Day of Week | 5 | 0–7 or SUN–SAT (0 and 7 = Sunday) | * , - / ? L # |
| Year (optional) | 6 | 1970–2099 | * , - / |
The fields are read left to right. A * means "every value in this field." Use this tool to paste any cron expression and get an instant plain-English explanation.
Cron Expression Examples
| Expression | Runs |
|---|---|
* * * * * | Every minute |
0 * * * * | Every hour at :00 |
0 9 * * * | Every day at 9:00 AM |
0 9 * * MON-FRI | Weekdays at 9:00 AM |
0 0 1 * * | First day of every month at midnight |
0 0 * * 0 | Every Sunday at midnight |
*/15 * * * * | Every 15 minutes |
0 8,12,17 * * * | At 8 AM, 12 PM, and 5 PM daily |
30 23 L * * | Last day of every month at 11:30 PM |
0 0 1 1 * | January 1st at midnight (once a year) |
Special Characters Explained
*— wildcard, matches every value.* * * * *runs every minute.,— list separator.MON,WED,FRImeans those three days.-— range.9-17means every hour from 9 to 17./— step.*/15means every 15 units;5/15means at 5, 20, 35, 50.?— no specific value (used in day-of-month or day-of-week to avoid conflicts).L— last. In day-of-month: last day of month. In day-of-week: last Friday =5L.W— nearest weekday.15W= the weekday nearest the 15th.#— nth occurrence.2#3= third Tuesday of the month.
Cron Syntax Differences by Platform
| Platform | Fields | Notes |
|---|---|---|
| Unix/Linux crontab | 5 (no year) | Standard. Minute Hour DOM Month DOW. |
| Spring (Java) | 6 (seconds first) | Adds seconds as first field. |
| Quartz Scheduler | 6 or 7 | Seconds first; optional year at end. |
| AWS EventBridge | 6 (cron) or rate() | Either cron() or rate(5 minutes) syntax. |
| GitHub Actions | 5 | Standard 5-field syntax in schedule. |
| Azure Logic Apps | 6 (seconds first) | Seconds field first like Quartz. |
| GCP Cloud Scheduler | 5 | Standard Unix cron syntax with timezone support. |
Always confirm which syntax your platform expects — the position of seconds (if any) is the most common source of off-by-one scheduling errors.
Scheduling and Automation Tools
Cron expression parsing fits into a broader scheduling and automation workflow:
- Convert scheduled timestamps — translate cron run times from Unix epoch to readable dates
- Format the SQL that your scheduled jobs execute
- Test cron patterns with regex — validate cron string format before deploying
Related Tools
- Scheduling CSV-to-JSON conversion jobs? Verify the cron expression first, then implement. → process scheduled data exports from CSV
- Automating JSON to CSV exports? Validate your cron schedule with the Cron Parser. → schedule recurring JSON export jobs
- Documenting your scheduled tasks? Write the cron reference in Markdown and convert to HTML. → document cron jobs in Markdown
- Passing cron expressions through an API URL? URL-encode them to prevent parsing issues. → encode cron expression values for APIs
- Migrating a VB.NET scheduled job system to C#? Convert the code and update the cron expressions. → convert VB.NET scheduler code to C#
Related Guides
Cron Expressions Explained: A Complete Reference
Every cron field, operator, and common pattern — with examples for backup jobs, reports, and cleanup tasks.
TutorialScheduling Tasks in the Cloud: AWS EventBridge, GitHub Actions, and Heroku Scheduler
How to write and debug cron schedules across the most popular platforms.
GuideUnix Timestamps: What Every Developer Needs to Know
Cron schedules and timestamps work together in almost every backend system.
Frequently Asked Questions
*/5 * * * * — the / step operator divides the minute field into intervals of 5. This runs at :00, :05, :10, :15... every hour.*/1 and * are equivalent — both mean "every value." */1 is redundant but valid.L special character in the day-of-month field: 0 23 L * * runs at 11 PM on the last day of each month. Note: L is supported in Quartz, Spring, and some cron implementations, but not in standard Unix crontab.0 and 7 represent Sunday in most cron implementations. This is a historical quirk. In standard Unix crontab, 0 = Sunday. Quartz and some other implementations also accept 7 for Sunday. Using 0 is the safest choice for compatibility.