What is the cron expression for the 1st and 15th?

The expression is 0 0 1,15 * *. The comma creates a list of day-of-month values.

Is this the same as every 2 weeks?

Not exactly. The 1st and 15th have 14-16 days between them depending on the month, while every 2 weeks is always 14 days. They also fall on different days of the week each month.

Cron 1st and 15th of Every Month

0 0 1,15 * *

On day 1st, 15th of every month at 12:00 AM

Next 10 Executions

Times shown in UTC

Mon, Jun 1, 202600:00
Mon, Jun 15, 202600:00
Wed, Jul 1, 202600:00
Wed, Jul 15, 202600:00
Sat, Aug 1, 202600:00
Sat, Aug 15, 202600:00
Tue, Sep 1, 202600:00
Tue, Sep 15, 202600:00
Thu, Oct 1, 202600:00
Thu, Oct 15, 202600:00

Field Breakdown

0

Minute

0

Hour

1,15

Day of Month

1,15

*

Month

Every month

*

Day of Week

Every day of week

About This Schedule

The cron expression 0 0 1,15 * * fires at midnight on the 1st and 15th of every month. The list 1,15 in the day-of-month field targets these two specific dates, creating a reliable semi-monthly schedule.

Semi-monthly schedules are standard in payroll (many companies pay on the 1st and 15th), billing cycles, mortgage processing, and financial reporting. The 1st and 15th split the month roughly in half, with 14-16 days between runs depending on the month.

This is more predictable than */14 in the day field, which runs on days 1, 15, and 29. If you need a different time, change the hour: 0 9 1,15 * * runs at 9 AM instead of midnight. For quarterly processing, see 0 0 1 1,4,7,10 *.