Format: minute hour day month day-of-week
Every 5 minutes, every hour, every day
Thu, Mar 19, 2026, 02:30:00
in 1 minute
Thu, Mar 19, 2026, 02:35:00
in 6 minutes
Thu, Mar 19, 2026, 02:40:00
in 11 minutes
Thu, Mar 19, 2026, 02:45:00
in 16 minutes
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*,1,3,5 = 1, 3, and 5-1-5 = 1 through 5/*/5 = every 5 units0-590-231-311-12 or JAN-DEC0-6 or SUN-SATShowing 8 of 94 related tools
Parse cron expressions in 30 seconds
Paste or type your cron expression in standard 5-field or extended 6-7 field format. Supports minute, hour, day of month, month, day of week, and optional year/second fields. Accepts standard operators: * (any), - (range), , (list), / (step).
Tool automatically parses the cron syntax and validates field values. Detects invalid ranges (e.g., minute > 59), incorrect field counts, or malformed operators. Provides immediate feedback on syntax errors with helpful correction hints.
See plain English description of when the job runs. Example: '0 9 * * 1' becomes 'At 09:00, only on Monday'. Helps verify cron logic matches intended schedule before deployment.
View upcoming execution timestamps (next 5-10 runs) calculated from current time. Useful for confirming schedule timing, checking timezone handling, or debugging why a job didn't run as expected.
Understanding cron expression syntax
Cron expression parsing converts Unix cron syntax into human-readable schedules and calculates execution times. Cron is the time-based job scheduler in Unix-like operating systems, used to run scripts, commands, or tasks at fixed times, dates, or intervals. Understanding cron syntax is essential for DevOps, backend development, and automated task scheduling.
Software developers encounter cron expressions when configuring: CI/CD pipeline schedules (GitHub Actions, GitLab CI), cloud job schedulers (AWS EventBridge, GCP Cloud Scheduler), backup automation, database maintenance tasks, log rotation scripts, monitoring health checks, webhook retries, email campaign delivery, cache invalidation jobs, and report generation tasks.
Scheduled job automation: Backend systems rely on cron for recurring tasks. Example: run database backups daily at 2 AM, clean up old logs every Sunday at midnight, send weekly summary emails every Monday at 9 AM, refresh cache every 15 minutes. Incorrect cron syntax causes jobs to run at wrong times, skip entirely, or run too frequently, leading to data loss, performance issues, or service disruptions.
Cloud scheduler configuration: AWS EventBridge, GCP Cloud Scheduler, Azure Functions Timer Triggers all use cron expressions. Configuring '0 9 * * *' schedules a job at 9 AM daily. But '0 9 * * 1' only runs Mondays. Understanding syntax differences prevents costly mistakes. Cloud platforms charge per execution - incorrect cron can cause thousands of unexpected runs.
GitHub Actions scheduling: CI/CD workflows use cron syntax for scheduled runs. Example: schedule: [{cron: '0 0 * * 0'}] runs tests every Sunday at midnight. But cron uses UTC timezone, not your local time. Parsing helps verify: does '0 9 * * *' mean 9 AM UTC or 9 AM EST? Timezone confusion causes workflows to run at unexpected hours.
Kubernetes CronJobs: Kubernetes CronJob resources use cron syntax to schedule pod execution. Example: daily database backup job, periodic health checks, scheduled scaling operations. Invalid cron syntax causes job creation to fail silently or jobs to never run. Parsing validates syntax before deployment and prevents production issues.
Debugging schedule issues: When a scheduled job doesn't run as expected, cron parsing helps diagnose: Is syntax correct? Does timezone match expectations? Are there conflicting field values? Does expression actually produce the desired schedule? Parsing tool shows next execution times to verify timing matches intent.
Standard 5-field format: minute hour day_of_month month day_of_week
Example: 30 14 * * 5 = At 14:30 (2:30 PM) every Friday
Extended 6-field format (with seconds): second minute hour day_of_month month day_of_week
Example: 0 30 14 * * 5 = At 14:30:00 every Friday (precise to second)
7-field format (with year): minute hour day_of_month month day_of_week year
Example: 0 9 1 1 * 2025 = At 09:00 on January 1st, 2025 only
Asterisk (*): Matches any value. * * * * * = every minute of every day.
Comma (,): Value list. 0 9,17 * * * = At 09:00 and 17:00 daily.
Hyphen (-): Range. 0 9-17 * * * = Every hour from 09:00 to 17:00.
Slash (/): Step values. */15 * * * * = Every 15 minutes. 0 */2 * * * = Every 2 hours.
Question mark (?): Only in day_of_month or day_of_week (some implementations). Means "no specific value". Used when specifying one day field but not the other. Example: 0 9 15 * ? = 9 AM on 15th of every month (day of week doesn't matter).
L: Last (day of month or week, some implementations). 0 0 L * * = Midnight on last day of month.
W: Weekday nearest to given day (some implementations). 0 9 15W * * = 9 AM on weekday nearest to 15th.
Hash (#): Nth occurrence of day (some implementations). 0 9 * * 1#2 = 9 AM on second Monday of month.
Every minute: * * * * *
Every 5 minutes: */5 * * * *
Every hour at minute 0: 0 * * * *
Every day at midnight: 0 0 * * *
Every day at 2:30 AM: 30 2 * * *
Every Monday at 9 AM: 0 9 * * 1
First day of month at midnight: 0 0 1 * *
Every weekday at 9 AM: 0 9 * * 1-5
Every 15 minutes during business hours: */15 9-17 * * 1-5
Twice daily (9 AM and 5 PM): 0 9,17 * * *
UTC vs Local Time: Most cloud schedulers use UTC timezone. If you're in EST (UTC-5), a cron of 0 9 * * * runs at 4 AM EST (9 AM UTC), not 9 AM EST. Always verify timezone settings in scheduler configuration. Some platforms allow timezone specification: TZ=America/New_York 0 9 * * * (syntax varies by platform).
Daylight Saving Time: Cron doesn't automatically adjust for DST. When clocks "spring forward" (2 AM becomes 3 AM), jobs scheduled at 2:30 AM skip that day. When clocks "fall back" (2 AM occurs twice), jobs at 2:30 AM may run twice. Design critical jobs around DST transitions.
Distributed systems: In multi-region deployments, every server runs cron in its local or configured timezone. Ensure consistent timezone configuration across all nodes or use UTC universally to avoid race conditions or duplicate executions.
This tool parses cron expressions, validates syntax, provides human-readable descriptions, and calculates next execution times to help developers verify scheduled task timing before deployment.
How developers use cron parsing
GitHub Actions uses cron syntax for scheduled workflows, but runs in UTC timezone. Parse cron expressions to verify workflow timing matches your intent, avoiding timezone confusion and ensuring CI runs at expected hours.
AWS EventBridge uses cron expressions to trigger Lambda functions, ECS tasks, or Step Functions on schedules. Parse expressions to ensure correct timing for automated backups, data processing, or periodic maintenance tasks.
Kubernetes CronJobs use cron syntax to schedule pod execution. Parse expressions to verify correct timing, debug jobs that don't run as expected, and ensure timezone configuration matches cluster settings.
Applications with user-facing scheduling features need cron validation. Parse user-entered expressions to validate syntax, show human-readable descriptions, and prevent invalid schedules before saving to database.
Master cron expression parsing
This tool parses cron expressions, validates syntax, provides human-readable descriptions, and calculates next execution times. Helps verify scheduled task timing before deployment.
Paste your cron expression in standard format. Supports:
minute hour day_of_month month day_of_weeksecond minute hour day_of_month month day_of_weekminute hour day_of_month month day_of_week yearExamples:
0 9 * * * - Daily at 9 AM*/15 * * * * - Every 15 minutes0 9 * * 1-5 - Weekdays at 9 AM0 0 1 * * - First day of month at midnightSyntax check: Tool validates field values are within valid ranges. Minute 0-59, hour 0-23, day 1-31, month 1-12, day_of_week 0-6. Rejects invalid values like minute 60 or hour 25.
Field count: Detects incorrect field counts. Standard cron is 5 fields. Some implementations support 6 (with seconds or year) or 7. Tool identifies format and validates accordingly.
Operator validation: Checks special characters are used correctly. Slash (/) must have valid step values. Ranges (-) must be min to max. Lists (,) must have valid values.
Tool converts cron syntax to plain English:
0 9 * * * → "At 09:00"0 9 * * 1 → "At 09:00, only on Monday"*/15 * * * * → "Every 15 minutes"0 9 * * 1-5 → "At 09:00, Monday through Friday"0 0,12 * * * → "At 00:00 and 12:00"Verify description matches your intended schedule before deploying.
Tool calculates upcoming execution timestamps based on current time. Shows next 5-10 runs with date and time. Useful for:
Timezone note: Most cloud schedulers use UTC. If next execution shows 09:00 UTC but you expected 09:00 EST, adjust cron expression to account for timezone offset.
Periodic intervals:
* * * * **/5 * * * *0 * * * *0 */2 * * *Daily schedules:
0 0 * * *30 2 * * *0 9,17 * * *Weekly schedules:
0 9 * * 10 9 * * 1-50 12 * * 0,6Monthly schedules:
0 0 1 * *0 9 15 * *Timezone confusion: Cloud schedulers often use UTC. Convert local time to UTC when writing cron. Example: 9 AM EST = 2 PM UTC during standard time, 1 PM UTC during daylight saving.
Day of week vs day of month: When both are specified (not *), some implementations use OR logic (either matches), others use AND (both must match). Test behavior in your specific platform.
Minute vs hour confusion: 0 9 * * * means 9 AM (hour 9, minute 0), not 9 minutes past midnight. Use 24-hour format: 2 PM = hour 14.
Step value misunderstanding: */15 * * * * runs at :00, :15, :30, :45 each hour. It doesn't run "every 15 minutes starting now" - it aligns to clock boundaries.
Everything you need to know about cron
Your data never leaves your browser
All cron expression parsing happens entirely in your browser using client-side JavaScript. Zero server communication, zero data transmission, zero logging.
Safe for parsing confidential job schedules, proprietary automation tasks, internal system cron configurations, or production infrastructure scheduling. Use with confidence for sensitive DevOps workflows or critical scheduled jobs.
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