Cron on January 1st and July 1st

The cron expression 0 0 1 1,7 * schedules a task to run twice per year, at midnight on January 1st and July 1st.

Field-by-field breakdown:

• 0 (Minute): At minute 0. The task fires at the top of the hour.
• 0 (Hour): At hour 0 (midnight / 12 AM). The task runs at the very start of the day.
• 1 (Day of Month): On the 1st day of the month. The task is anchored to the first of the month.
• 1,7 (Month): In January and July only. The list notation specifies two months, exactly 6 months apart, creating a semi-annual schedule.
• * (Day of Week): Every day of the week. No restriction on the day.

This means your task will execute exactly twice per year: at midnight on January 1st and at midnight on July 1st. This semi-annual schedule divides the year into two equal halves and is commonly used for tasks aligned with half-year business cycles. Examples include semi-annual performance review triggers, half-year financial report generation, bi-annual security certificate rotation, and mid-year budget review automation. The January/July split aligns with both calendar half-years and many organizations' fiscal planning cycles. This pattern can be adapted for any two-month combination by changing the month values. This expression is supported by standard cron on Linux/macOS, as well as cloud services like AWS CloudWatch, Google Cloud Scheduler, and GitHub Actions.