Clear English Translation for Complex Schedules
Demystify confusing step values (*/15), ranges (1-5), and comma lists with an immediate natural language description.
Cronjob Explainer & Generator
Free online Cronjob Explainer and Generator. Convert cron expressions into plain English sentences, view next 5 run dates, and build crontab schedules visually.
Crontab Expression (5 Fields)Valid 5-field syntax
Popular Schedule Presets:
Human Translation
Runs every 15 minutes, at 12:00 AM, on day 1,15 of month, on Monday through Friday.
5-Field Syntax Breakdownmin · hr · dom · mon · dow
Minute
*/15
0–59
every 15 minutes
Hour
0
0–23
at 12:00 AM
Day of Month
1,15
1–31
on day 1,15 of month
Month
*
1–12 (Jan–Dec)
every month
Day of Week
1-5
0–6 (Sun=0)
on Monday through Friday
Crontab Operators Quick Reference
*
Any value
Match every unit
,
Value list
e.g. 1,15,30
-
Range
e.g. 1-5 (Mon–Fri)
/
Step / Interval
e.g. */15 (every 15)
Next 5 Scheduled RunsUTC
1Mon, Nov 2, 12:00:00 AM
in 22h 0m2Mon, Nov 2, 12:15:00 AM
in 22h 15m3Mon, Nov 2, 12:30:00 AM
in 22h 30m4Mon, Nov 2, 12:45:00 AM
in 22h 45m5Tue, Nov 3, 12:00:00 AM
in 1 dayDeveloper Scenario: Deciphering a Complex Database Backup Cron Schedule
A systems engineer inspects a legacy server crontab line: `15 3 1,15 * 1-5` and needs to verify when the maintenance script triggers.
| Expression | 15 3 1,15 * 1-5 |
| Human Explanation | At 03:15 AM, on day 1 and 15 of the month, and Monday through Friday. |
| Upcoming Next Runs | 1. Mon, Nov 2, 2026, 03:15 AM 2. Tue, Nov 3, 2026, 03:15 AM 3. Sun, Nov 15, 2026, 03:15 AM |
💡 The explainer eliminates guesswork, guaranteeing that backup scripts execute at intended off-peak maintenance hours.
How to use Cronjob Explainer & Generator
- 1
Enter any 5-field (standard Unix/Linux) or 6-field cron expression into the input field, or choose from popular preset schedules.
- 2
Read the instant human-readable English explanation breaking down minutes, hours, days, months, and weekdays.
- 3
Examine the calculated upcoming run times list showing exact execution dates, hours, and relative countdowns in your local timezone.
Why use this tool?
Upcoming Execution Forecast
Preview the next 5 to 10 scheduled execution timestamps calculated against your current system clock in both local and UTC time.
Interactive Crontab Builder & Presets
Select common schedules (hourly, daily at midnight, weekly, monthly) or use intuitive dropdown controls to build cron lines without memorizing syntax.
Continue your workflow
Validating input strings or cron log outputs? Check out the Test regular expressions in real time.
Need to structure scheduled cron event payloads in JSON? Use the Format and validate JSON payloads.
Auditing changes across server crontab configuration files? Try the Compare crontab file versions.
Triggering external HTTP webhooks via scheduled jobs? Use the Encode webhook URLs.
Crontab Expression Syntax Field Guide
Standard 5-field order and allowed values for Linux crontab configurations.
| Field Position | Field Name | Allowed Values | Special Characters Allowed |
|---|---|---|---|
| 1st | Minute | 0 - 59 | * , - / |
| 2nd | Hour | 0 - 23 | * , - / |
| 3rd | Day of Month | 1 - 31 | * , - / L W |
| 4th | Month | 1 - 12 or JAN - DEC | * , - / |
| 5th | Day of Week | 0 - 6 (0 = Sunday) or SUN - SAT | * , - / L # |
Field positions are separated by a single space. Comments can be added with # at the start of a line.
Frequently asked questions
What are the 5 standard fields of a crontab expression?
In standard Unix/Linux crontab, the 5 fields are: (1) Minute (0-59), (2) Hour (0-23), (3) Day of the Month (1-31), (4) Month (1-12 or JAN-DEC), and (5) Day of the Week (0-6 where 0 is Sunday, or SUN-SAT).
What does the asterisk (*) and slash (/) mean in cron?
An asterisk (*) represents every possible value for that field (e.g. * in the hour field means every hour). A forward slash followed by a number (/n) indicates step intervals (e.g. */15 in the minute field means every 15 minutes).
Is Sunday represented by 0 or 7 in cron?
Standard Unix crontab accepts 0 for Sunday. Many implementations (including Vixie cron and AWS EventBridge) accept both 0 and 7 to represent Sunday.
Can this tool calculate upcoming run times across leap years?
Yes. The scheduling engine accurately accounts for varying month lengths (28, 29, 30, 31 days) and leap years when projecting upcoming run dates.
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