Time & Date
Cron Expression Calculator
Build, parse and validate cron expressions with human-readable descriptions and next run times
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What does * mean?
Asterisk means 'every' - so * in minute field means every minute.
What is */5?
Step value - */5 in minute field means every 5 minutes (0, 5, 10, 15...).
What is L in day field?
L means 'last' - L in day-of-month means last day of the month.
Related tools
About this tool
Inputs
- Mode
- Minute
- Hour
- Day of Month
- Month
- Day of Week
- Cron Expression
- Builder
- Parser
- Presets
Results
- Expression
- Description
- Next Runs
- Frequency
Figuring out build, parse and validate cron expressions with human-readable descriptions and next run times no longer requires manual arithmetic. The Cron Expression Calculator walks you through the math step by step. Start by filling in mode, minute, hour, day of month, month, day of week, cron expression, builder, parser and presets. Based on these values, the tool computes expression, description, next runs and frequency. Workday calculations typically exclude weekends (Saturday and Sunday) and may also exclude public holidays. The Gregorian calendar adds a leap day every 4 years, except for century years not divisible by 400.
For scheduling across timezones, store in UTC and convert for display. People frequently need to build, parse and validate cron expressions with human-readable descriptions and next run times but lack a quick way to do it — this tool fills that gap. Duration calculations should distinguish between calendar duration (months, years) and exact duration (days, seconds). Use the result as a starting point for deeper analysis. Pair it with other tools for a more complete picture. Be careful with "months" as a unit — adding one month to January 31 does not have a clear answer.