Cron Expression to Plain English Human Translator
Translate complex crontab expressions (e.g., 0 0 1,15 * ?) into clear, natural human sentences with upcoming execution timestamps. 100% private, instant browser computation.
Plain English Translation
Human-readable execution meaning
Field-by-Field Syntax Breakdown
At minute 0
At 00:00 (12:00 AM)
On the 1st and 15th of the month
Every month
Any value (no specific condition / ignore)
Upcoming Execution Timestamps
Calculated scheduled trigger times starting from current reference time
Cron Expression Anatomy & Syntax Reference
Understanding POSIX standard 5-part crontab vs Quartz/Spring 6-part scheduling syntax.
| Position | Field Name | Allowed Values | Allowed Special Characters | Example |
|---|---|---|---|---|
| 1 | Minute | 0 - 59 | * , - / | */15 |
| 2 | Hour | 0 - 23 | * , - / | 9-17 |
| 3 | Day of Month | 1 - 31 | * , - / ? L W | 1,15 |
| 4 | Month | 1 - 12 or JAN - DEC | * , - / | JAN,JUN |
| 5 | Day of Week | 0 - 7 (0 & 7 = Sun) or SUN - SAT | * , - / ? L # | 1-5 (Mon-Fri) |
| Optional 0/6 | Second (Quartz) | 0 - 59 | * , - / | 0 |
Special Characters Cheat Sheet
Matches any possible value in the specified field.
Specifies discrete items (e.g. 1,15 means day 1 and day 15).
Defines an inclusive span (e.g. 9-17 means 9 through 17).
Increments values (e.g. */10 in minutes means every 10 mins).
Used in Quartz DOM or DOW to avoid specifying a constraint.
Matches the last day of month or last specific weekday (e.g. 5L).
Matches the closest workday (Mon-Fri) to the specified date.
Specifies the nth weekday of the month (e.g. 2#1 is 1st Monday).
Frequently Asked Questions (FAQ)
What does "0 0 1,15 * ?" mean?
It triggers at midnight (00:00) on the 1st and 15th calendar days of every month. The question mark "?" is the Quartz wildcard specifying "no specific day-of-week constraint".
Can I paste a full crontab line containing a command?
Yes! The parser automatically identifies and isolates trailing shell commands (such as "/usr/bin/backup.sh"), translating the scheduling pattern while providing one-click copy for the script command.
What is the difference between * and ? in crontab?
"*" stands for "all possible values" in standard Unix POSIX crontab. In Quartz and AWS EventBridge schedules, "?" is used in either Day-of-Month or Day-of-Week to explicitly indicate that the field should be ignored.
Is any data stored or sent to a server?
Zero data is sent. The parser and next-run projection algorithms run 100% inside your client browser JavaScript engine, guaranteeing total privacy and offline functionality.