Cron Expression Generator: Visual Guide for 2026

Cron jobs are heartbeat of automated systems—database backups, email reports, scheduled deployments, cleanup scripts. But writing cron expressions manually? It’s like memorizing a foreign language you only speak once a month.

Our Cron Generator transforms cryptic syntax into an intuitive visual builder, so you can schedule tasks confidently without memorization.

What Are Cron Jobs?

Cron is a time-based job scheduler in Unix-like systems. You define a “cron expression” (a text string) that specifies when a command should run. The cron daemon checks every minute and executes matching tasks.

The 5-Field Structure

Every cron expression has exactly five fields, in this order:

┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of week (0 - 7) (Sunday = 0 or 7)
* * * * * *

Each field accepts:

• Single value: 9 (9th minute)
• Range: 1-5 (minutes 1 through 5)
• List: 1,15,30,45 (minutes 1, 15, 30, and 45)
• Wildcard (*): Every possible value
• Step: */15 (every 15 minutes)

Why Manual Cron Writing Is Frustrating

The “What Does This Mean?” Problem

You find a cron example online: 0 9 * * 1-5. You copy it. But what does 1-5 mean? Is it Monday through Friday? Is it days 1, 2, 3, 4, and 5?

Without context, you’re guessing. And if you guess wrong, your scheduled task runs at the wrong time—or not at all.

The “Wait 24 Hours” Debugging Loop

You deploy a cron job. You realize it should run daily at midnight. You set 0 0 * * *. You wait. Next day comes. No task ran. Did cron break? Is your syntax wrong?

You’re stuck modifying cron expressions, deploying, waiting, checking logs, repeating. Hours wasted.

The Edge Case Traps

Cron has nuanced rules that trip up even experienced developers:

• Day of Month vs Day of Week: If both are specified (not *), cron runs when either is true (OR logic, not AND).
• Time Zones: Cron runs in server’s timezone. If your server is UTC but you’re in PST, your “9 AM” job runs at 1 AM your time.
• February 30th: Cron doesn’t validate dates. Your job scheduled for the 30th won’t run in February.

Our Cron Generator visualizes all these fields, so you see exactly what each component means in plain English.

Building Cron Expressions Visually

Minute (0-59)

Controls what minute of the hour the task runs.

Examples from our Cron Generator:

• 0 = Exactly at the top of the hour
• */15 = Every 15 minutes (0, 15, 30, 45)
• 30 = At minute 30 (half-past)
• 0,30 = At minute 0 and 30 (every 30 minutes)

Hour (0-23)

Controls what hour of the day the task runs.

• 9 = At 9 AM (9:00)
• 18 = At 6 PM (18:00)
• */6 = Every 6 hours (0, 6, 12, 18)
• 8-17 = Hours 8 through 17 (business hours only)

Day of Month (1-31)

Controls which day of the month the task runs.

• 1 = On the 1st of each month
• 15 = On the 15th of each month
• * = Every day of the month

Pro Tip: Using 1 for “first of month” is common for billing cycles, monthly reports, or cleanup scripts that need to run after previous month’s data is processed.

Month (1-12)

Controls which month the task runs.

• 1 = January
• 6 = June
• 12 = December
• */3 = Every 3 months (January, April, July, October)

Pro Tip: Use */3 or */6 for quarterly schedules without hardcoding specific months.

Day of Week (0-7)

Controls which weekday the task runs. Note: Both 0 and 7 represent Sunday in most implementations.

• 0 or 7 = Sunday
• 1 = Monday
• 5 = Friday
• 1-5 = Monday through Friday (business days)
• */2 = Every 2 days (Sunday, Tuesday, Thursday, Saturday)

Pro Tip: Use 1-5 in our Cron Generator to exclude weekends for business-only automation.

Quick Presets for Common Schedules

Our Cron Generator includes presets for frequently-needed schedules. Instead of building from scratch, click a preset and customize.

Every Minute

Expression: * * * * *

Runs: Every single minute, all day, every day. Use Case: Real-time monitoring, heartbeat checks, queue processing.

Every Hour

Expression: 0 * * * *

Runs: At the top of every hour (00 minutes). Use Case: Hourly data aggregation, cache invalidation, status checks.

Daily at Midnight

Expression: 0 0 * * *

Runs: At 00:00 (midnight) every day. Use Case: Daily backups, midnight batch jobs, end-of-day reporting.

Daily at 9 AM

Expression: 0 9 * * *

Runs: Every day at 9:00 AM. Use Case: Morning reports, daily email digests, business-day kickoff tasks.

Every Weekday at 9 AM

Expression: 0 9 * * 1-5

Runs: Monday through Friday at 9:00 AM. Excludes Saturday and Sunday. Use Case: Business-hours-only automation, excluding weekends for production deployments.

Every Monday at 9 AM

Expression: 0 9 * * 1

Runs: Every Monday at 9:00 AM. Use Case: Weekly meetings, weekly reports, Monday maintenance tasks.

First of Month at Midnight

Expression: 0 0 1 * *

Runs: On the 1st of every month at midnight. Use Case: Monthly billing, monthly newsletters, monthly data archiving.

Every 15 Minutes

Expression: */15 * * * *

Runs: At minutes 0, 15, 30, and 45 of every hour. Use Case: Frequent queue processing, cache refresh, heartbeat monitoring.

All these presets are available in our Cron Generator—click, then customize as needed.

Advanced Cron Patterns

Cron Shortcuts (Special Characters)

Certain special characters save time:

• @yearly or @annually: 0 0 1 1 * (once a year)
• @monthly: 0 0 1 * * (once a month)
• @weekly: 0 0 * * 0 (once a week, Sunday)
• @daily or @midnight: 0 0 * * * (daily at midnight)
• @hourly: 0 * * * * (every hour)

Multiple Values (Lists)

Run task at specific multiple times:

Expression: 0,30 * * * *

Runs: At minute 0 AND minute 30 of every hour (every 30 minutes).

Use Case: High-frequency tasks that need to run twice hourly but not every minute.

Range Expressions

Run task during a range of values:

Expression: 0 9-17 * * 1-5

Runs: Every minute 0 of hours 9 through 17, Monday through Friday. Use Case: Business-hours-only tasks that run every hour during workdays.

Step Intervals

Run task at regular intervals:

Expression: */15 * * * *

Runs: Every 15 minutes (0, 15, 30, 45). Use Case: Periodic tasks that don’t need to run as frequently as every minute but more than once per hour.

Cron Gotchas and Best Practices

Time Zone Awareness

Cron expressions don’t include time zone information. They run in the server’s local time.

Problem: Your server is in UTC. You set a job for 0 9 * * * thinking it’ll run at 9 AM your time (Pacific). But it actually runs at 9 AM UTC (2 AM Pacific).

Solution: Either:

1. Set cron based on server’s time zone
2. Use a tool like TZ=US/Pacific 0 9 * * * (if your cron daemon supports it)
3. Adjust expression manually (9 AM Pacific = 5 PM UTC = 0 17 * * *)

February 30th Problem

Cron doesn’t validate dates. You can schedule a job for the 30th of every month. In February (28 or 29 days), that job simply doesn’t run.

Solution: Use 28 instead of 30 for monthly tasks, or use @monthly shortcut which handles this.

Day of Month AND Day of Week

If both day of month AND day of week are specified (neither is *), cron runs when either condition is true.

Expression: 0 9 1 * 1

This runs: On the 1st of the month OR every Monday.

Problem: This is rarely what you want. You might think it means “Monday of the 1st week” but it doesn’t.

Solution: Use only one of the fields, not both, unless you intentionally want this OR behavior.

Our Cron Generator clarifies these behaviors with plain-English explanations.

Testing Cron Expressions

Before deploying to production, test locally:

1. Use the Crontab Command

crontab -e

Add your expression and a command to test.

2. Check Logs

tail -f /var/log/syslog | grep CRON

Watch for your job executing.

3. Use Online Testers

Paste your expression into a cron tester (not our tool, as we generate expressions). These tools show next execution times, letting you verify your logic before deployment.

4. Start with High Frequency

For initial testing, use */1 * * * * (every minute) or */5 * * * * (every 5 minutes). Once confirmed it works, adjust to your desired schedule.

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Frequently Asked Questions

Q: How do I write a cron expression to run daily at midnight?

A: Use 0 0 * * * in our Cron Generator. This means: run at minute 0 (top of hour) of hour 0 (midnight), every day, every month. You can also use the “Daily at Midnight” preset for one-click setup.

Q: What does */15 mean in cron expressions?

A: The */15 syntax means “every 15th value” or “every interval of 15.” In the minute field, it runs at minutes 0, 15, 30, and 45 of every hour. In the hour field, */6 means every 6 hours (0, 6, 12, 18). Use our Cron Generator to set intervals visually.

Q: How do I schedule a job to run only on weekdays?

A: In our Cron Generator, use 1-5 for the “Day of Week” field. This represents Monday (1) through Friday (5). Saturday (6) and Sunday (0 or 7) are excluded. You can combine this with time constraints: 0 9 * * 1-5 runs Monday through Friday at 9 AM.

Q: What’s the difference between @daily and 0 0 * * *?

A: They’re identical. @daily is a shortcut alias for 0 0 * * * (run at minute 0 of hour 0, every day, every month, every day of week). Other shortcuts include @hourly (0 * * * *), @weekly (0 0 * * 0), @monthly (0 0 1 * *), and @yearly (0 0 1 1 *). Our Cron Generator supports both shortcuts and manual expressions.

Q: How do I schedule a cron job for the first of every month?

A: Use 0 0 1 * * in our Cron Generator. This means: minute 0, hour 0 (midnight), day 1, any month, any weekday. This runs on the 1st of every month at midnight. We also have a “First of Month at Midnight” preset for one-click setup.

Q: Why doesn’t my cron job run when expected?

A: Common causes include: time zone mismatch (cron uses server time, not yours), invalid syntax errors, or trying to run on non-existent dates (like February 30th). Use our Cron Generator to verify your expression, check server logs, and ensure your time zone matches expectations. The tool explains what each field means in plain English, making debugging easier.

Q: How do I create a cron expression that runs every 30 minutes?

A: Use 0,30 * * * * or */30 * * * * in our Cron Generator. Both expressions mean the same thing: run at minute 0 AND minute 30 of every hour. The comma syntax is more explicit, while the */ syntax is a shortcut for “every interval.” Try both to see which you prefer.

Q: What happens if I specify both day of month and day of week?

A: If both fields are specified (not *), cron runs when either condition is true (OR logic, not AND). For example, 0 9 1 * 1 runs on the 1st of the month OR every Monday, not “Monday of the 1st week.” If you want specific logic, use our Cron Generator to test and verify, or avoid specifying both fields.

Q: How do I test a cron expression without waiting 24 hours?

A: You can test cron expressions temporarily with high frequency (like */1 * * * * for every minute) to verify syntax and execution. Check logs immediately after saving. Our Cron Generator helps you build correct expressions before testing, reducing trial-and-error cycles. Once confirmed, adjust to your desired schedule.

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Start Scheduling Confidently

Cron expressions don’t need to be a mystery. With visual building, plain-English explanations, and tested presets, you can schedule tasks accurately on the first try.

Our Cron Generator is free, runs in your browser, and includes:

• Visual builder with dropdowns
• Plain-English explanation of each field
• Quick presets for common schedules
• Real-time preview of your expression

Start automating reliably today:

• Build Cron Expressions Visually - No memorization required
• Use Common Presets - Hourly, daily, weekly schedules
• Understand Cron Syntax - Each field explained clearly

Stop debugging cron jobs at 2 AM. Build schedules right the first time with our Cron Generator.

Explore all 16 free tools at Hasare.

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Scheduling automation shouldn’t require learning a new language. Use our visual Cron Generator to build reliable schedules instantly.