Documentation
How to use this tool, practical use cases, and technical notes.
Getting a valid crontab entry out of this tool takes under 5 minutes. Here is a complete step-by-step walkthrough covering every feature of the tool.
Step 1 — Choose a Preset (Optional but Recommended)
The tool offers six built-in presets for the most common scheduling patterns. Click any preset to instantly populate all five fields:
Preset Button | Cron Expression | Human Description | Typical Use Case |
|---|---|---|---|
Daily midnight |
| At minute 0, at midnight, every day | Daily database dumps, report generation |
Every 15 min |
| Every 15 minutes | Health checks, polling jobs, cache warming |
Weekdays 9 AM |
| At 9 AM, Monday through Friday | Business-hours notifications, daily standups |
Sunday 2 AM |
| At 2 AM on Sundays | Weekly backups, maintenance windows |
1st of month |
| At midnight on the 1st of every month | Monthly billing jobs, compliance reports |
Every hour |
| At minute 0 of every hour | Hourly syncs, log shipping, metric collection |
If your use case matches a preset, clicking it saves time and eliminates the risk of misconfiguration.
Step 2 — Customize Each Schedule Field
If no preset matches your needs, configure each of the five fields individually using the dropdown selectors:
Minute Field (0–59)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every minute |
| Job runs every minute — use with extreme caution |
At minute 0 |
| Runs at the top of whatever hour(s) match |
Every 5 minutes |
| Runs at :00, :05, :10, :15... |
Every 15 minutes |
| Runs at :00, :15, :30, :45 |
Every 30 minutes |
| Runs at :00, :30 |
Custom | Manual entry | Enter any valid minute value or expression |
Hour Field (0–23)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every hour |
| Runs at every hour |
Midnight |
| Runs at 12:00 AM |
2 AM |
| Runs at 2:00 AM |
9 AM |
| Runs at 9:00 AM |
Noon |
| Runs at 12:00 PM |
6 PM |
| Runs at 6:00 PM |
Custom | Manual entry | Any hour 0–23 |
Day of Month Field (1–31)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every day |
| Runs every day of the month |
1st of month |
| Runs on the 1st only |
15th of month |
| Runs on the 15th only |
Custom | Manual entry | Any day 1–31, or a list/range |
Month Field (1–12)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every month |
| Runs every month |
January |
| January only |
June |
| June only |
December |
| December only |
Custom | Manual entry | Any month 1–12, names, lists |
Day of Week Field (0–7)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every day |
| Runs regardless of weekday |
Sunday |
| Sundays only (note: |
Weekdays Mon–Fri |
| Monday through Friday |
Saturday |
| Saturdays only |
Custom | Manual entry | Any value 0–7 or range |
Step 3 — Add Your Command
In the Command field, enter the full absolute path to the script or command you want cron to execute. The tool pre-fills /usr/local/bin/backup.sh as a placeholder, but replace it with your actual command.
Critical rule: Always use absolute paths. Cron runs with a minimal environment and a stripped-down PATH that typically only includes /usr/bin and /bin. Commands that work in your shell terminal may silently fail under cron if they rely on a path that isn't in cron's minimal environment.
Step 4 — Read the Live Preview
As you configure each field, the tool updates two outputs in real time:
Human description (plain English): Tells you exactly when the job will run, e.g.:
"At minute 0, at 2 AM, on Sundays."
Cron expression: The complete five-field string ready for use, e.g.:
0 2 * * 0
Always read the human description before copying. It is the fastest way to catch misconfigurations — if the description doesn't match your intent, adjust the fields before copying.
Step 5 — Use a Common Command Preset (Optional)
The tool includes four common command templates that fill the Command field with real-world examples:
Command Preset | Command It Inserts | What It Does |
|---|---|---|
Backup script |
| Runs a custom backup shell script |
Certbot renew |
| Renews Let's Encrypt SSL certificates silently |
Log rotate |
| Rotates and compresses log files per config |
Curl healthcheck |
| HTTP GET to confirm service is responding |
These are production-ready command patterns used by Linux administrators worldwide.
Step 6 — Copy the Crontab Entry
The tool offers two copy options:
Option | What It Copies | When to Use |
|---|---|---|
Copy line |
| Ready to paste directly into your crontab file |
Copy with comments | Expression + inline comment explaining the schedule | Best when sharing crontab configs with your team or documenting in version control |
Step 7 — Install the Crontab Entry
Open your crontab for editing on your Linux server:
crontab -eThis opens your user-level crontab in the default editor (usually nano or vi). Paste the copied line at the end of the file, save, and exit. The cron daemon picks up the change automatically — no restart required.
To verify the entry was saved:
crontab -lTo edit the system-wide crontab (runs as root):
sudo crontab -eGetting a valid crontab entry out of this tool takes under 5 minutes. Here is a complete step-by-step walkthrough covering every feature of the tool.
Step 1 — Choose a Preset (Optional but Recommended)
The tool offers six built-in presets for the most common scheduling patterns. Click any preset to instantly populate all five fields:
Preset Button | Cron Expression | Human Description | Typical Use Case |
|---|---|---|---|
Daily midnight |
| At minute 0, at midnight, every day | Daily database dumps, report generation |
Every 15 min |
| Every 15 minutes | Health checks, polling jobs, cache warming |
Weekdays 9 AM |
| At 9 AM, Monday through Friday | Business-hours notifications, daily standups |
Sunday 2 AM |
| At 2 AM on Sundays | Weekly backups, maintenance windows |
1st of month |
| At midnight on the 1st of every month | Monthly billing jobs, compliance reports |
Every hour |
| At minute 0 of every hour | Hourly syncs, log shipping, metric collection |
If your use case matches a preset, clicking it saves time and eliminates the risk of misconfiguration.
Step 2 — Customize Each Schedule Field
If no preset matches your needs, configure each of the five fields individually using the dropdown selectors:
Minute Field (0–59)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every minute |
| Job runs every minute — use with extreme caution |
At minute 0 |
| Runs at the top of whatever hour(s) match |
Every 5 minutes |
| Runs at :00, :05, :10, :15... |
Every 15 minutes |
| Runs at :00, :15, :30, :45 |
Every 30 minutes |
| Runs at :00, :30 |
Custom | Manual entry | Enter any valid minute value or expression |
Hour Field (0–23)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every hour |
| Runs at every hour |
Midnight |
| Runs at 12:00 AM |
2 AM |
| Runs at 2:00 AM |
9 AM |
| Runs at 9:00 AM |
Noon |
| Runs at 12:00 PM |
6 PM |
| Runs at 6:00 PM |
Custom | Manual entry | Any hour 0–23 |
Day of Month Field (1–31)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every day |
| Runs every day of the month |
1st of month |
| Runs on the 1st only |
15th of month |
| Runs on the 15th only |
Custom | Manual entry | Any day 1–31, or a list/range |
Month Field (1–12)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every month |
| Runs every month |
January |
| January only |
June |
| June only |
December |
| December only |
Custom | Manual entry | Any month 1–12, names, lists |
Day of Week Field (0–7)
Dropdown Option | Expression | Meaning |
|---|---|---|
Every day |
| Runs regardless of weekday |
Sunday |
| Sundays only (note: |
Weekdays Mon–Fri |
| Monday through Friday |
Saturday |
| Saturdays only |
Custom | Manual entry | Any value 0–7 or range |
Step 3 — Add Your Command
In the Command field, enter the full absolute path to the script or command you want cron to execute. The tool pre-fills /usr/local/bin/backup.sh as a placeholder, but replace it with your actual command.
Critical rule: Always use absolute paths. Cron runs with a minimal environment and a stripped-down PATH that typically only includes /usr/bin and /bin. Commands that work in your shell terminal may silently fail under cron if they rely on a path that isn't in cron's minimal environment.
Step 4 — Read the Live Preview
As you configure each field, the tool updates two outputs in real time:
Human description (plain English): Tells you exactly when the job will run, e.g.:
"At minute 0, at 2 AM, on Sundays."
Cron expression: The complete five-field string ready for use, e.g.:
0 2 * * 0
Always read the human description before copying. It is the fastest way to catch misconfigurations — if the description doesn't match your intent, adjust the fields before copying.
Step 5 — Use a Common Command Preset (Optional)
The tool includes four common command templates that fill the Command field with real-world examples:
Command Preset | Command It Inserts | What It Does |
|---|---|---|
Backup script |
| Runs a custom backup shell script |
Certbot renew |
| Renews Let's Encrypt SSL certificates silently |
Log rotate |
| Rotates and compresses log files per config |
Curl healthcheck |
| HTTP GET to confirm service is responding |
These are production-ready command patterns used by Linux administrators worldwide.
Step 6 — Copy the Crontab Entry
The tool offers two copy options:
Option | What It Copies | When to Use |
|---|---|---|
Copy line |
| Ready to paste directly into your crontab file |
Copy with comments | Expression + inline comment explaining the schedule | Best when sharing crontab configs with your team or documenting in version control |
Step 7 — Install the Crontab Entry
Open your crontab for editing on your Linux server:
crontab -eThis opens your user-level crontab in the default editor (usually nano or vi). Paste the copied line at the end of the file, save, and exit. The cron daemon picks up the change automatically — no restart required.
To verify the entry was saved:
crontab -lTo edit the system-wide crontab (runs as root):
sudo crontab -e