What is Month Field?
The fourth field in a cron expression, specifying which months (1-12 or JAN-DEC) the job runs.
Definition
The month field is the fourth field in a cron expression, accepting numeric values 1-12 or three-letter abbreviations (JAN, FEB, MAR, etc.). It restricts job execution to specific months. Using * means every month. Ranges (1-6 for first half of year) and lists (3,6,9,12 for quarterly) are supported.
Simple Analogy
Like marking specific months on a yearly planner — the job is only active during the highlighted months.
Why It Matters
The month field enables seasonal scheduling: quarterly reports (3,6,9,12), tax filings (1,4), holiday promotions (11,12), or fiscal year boundaries. Most jobs use * for every month, but financial and compliance tasks often need specific months.
How to Verify
Verify with the Cron Explainer that the next runs span the correct months. For quarterly schedules, confirm runs in March, June, September, December (not January, April, July, October).
Common Mistakes
Using 0 for January — months start at 1, not 0. Confusing month abbreviations with day-of-week abbreviations (JAN is month, MON is day). Setting quarterly schedules to 1,4,7,10 when you meant fiscal quarters starting March (3,6,9,12).
Best Practices
Use numeric values (1-12) for clarity and portability across cron implementations. For quarterly jobs, explicitly document which quarter convention you are using. Combine month restrictions with specific day-of-month values for precise scheduling like "March 15th" (0 0 15 3 *).
Cron Expression Generator
Build your cron expression
Try it free →Frequently Asked Questions
What is Month Field?
The month field is the fourth field in a cron expression, accepting numeric values 1-12 or three-letter abbreviations (JAN, FEB, MAR, etc.). It restricts job execution to specific months. Using * means every month. Ranges (1-6 for first half of year) and lists (3,6,9,12 for quarterly) are supported.
Why does Month Field matter for cron jobs?
The month field enables seasonal scheduling: quarterly reports (3,6,9,12), tax filings (1,4), holiday promotions (11,12), or fiscal year boundaries. Most jobs use * for every month, but financial and compliance tasks often need specific months.
What are best practices for Month Field?
Use numeric values (1-12) for clarity and portability across cron implementations. For quarterly jobs, explicitly document which quarter convention you are using. Combine month restrictions with specific day-of-month values for precise scheduling like "March 15th" (0 0 15 3 *).
Related Terms
Cron Expression
A string of five fields that defines when a scheduled job should run.
Day of Month Field
The third field in a cron expression, specifying which calendar days (1-31) the job runs.
Day of Week Field
The fifth field in a cron expression, specifying which weekdays (0-7 or SUN-SAT) the job runs.