Cron expression for every quarter

Field breakdown

Next runs

How this schedule works

Cron evaluates the five fields of 0 0 1 */3 * — minute, hour, day of month, month, day of week — against the clock once a minute and starts the job on any minute where all five match, which cronstrue reads as "At 12:00 AM, on day 1 of the month, every 3 months": 4 runs per year. Day of month is pinned to 1 and the month field selects January, April, July, and October, while day of week stays an asterisk — so the run lands on whatever weekday that date happens to be, and never drifts to a neighbouring day.

When to use every quarter

Quarterly runs cover financial and usage reports, key rotation on a ninety-day rhythm, and recomputing retention cohorts once a quarter closes. Four runs a year is few enough that each one is effectively a scheduled event rather than routine automation. Settle two things up front: whether your quarters are calendar quarters, since the step form fires in January, April, July and October and a fiscal year starting elsewhere needs an explicit month list; and whether the job can be re-run by hand if the one attempt it gets in three months fails.

Common mistakes with every quarter

A step in the month field counts from month 1, so this schedule is locked to January, April, July and October. If your fiscal quarters start in February the expression is wrong by a month, and it will stay wrong for a year before anyone reconciles the numbers — write the months out as a list instead. The larger risk is rehearsal. A job that runs four times a year is almost never exercised: credentials expire between runs, upstream schemas change, and the first anyone hears of it is the quarter-end when the report is due. Make it runnable on demand, and run it deliberately.

Platform snippets

The same expression, ready to paste into the four schedulers that read five-field cron. The notes below each snippet are the ones that follow from this schedule; the cron expression generator lists every caveat for every platform.

name: Scheduled workflow
on:
  schedule:
    - cron: '0 0 1 */3 *'
  workflow_dispatch:

jobs:
  scheduled:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Run job
        run: echo "Running scheduled job"

apiVersion: batch/v1
kind: CronJob
metadata:
  name: my-cron-job
spec:
  schedule: "0 0 1 */3 *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
            - name: job
              image: my-image:latest
              command: ["/bin/sh", "-c", "echo Running"]
          restartPolicy: OnFailure

{
  "$schema": "https://openapi.vercel.sh/vercel.json",
  "crons": [
    {
      "path": "/api/cron",
      "schedule": "0 0 1 */3 *"
    }
  ]
}

# Edit your crontab: crontab -e
0 0 1 */3 * /path/to/command

# With logging:
0 0 1 */3 * /path/to/command >> /var/log/cron.log 2>&1

Variations

• 0 0 1 1,4,7,10 * At 12:00 AM, on day 1 of the month, only in January, April, July, and October The identical schedule with the months named outright. Four values is short enough that the list is the more honest form.
• 0 0 1 */6 * At 12:00 AM, on day 1 of the month, every 6 months January and July — twice a year rather than four times. The half-yearly counterpart, useful for slower key rotations.
• 0 0 1 2,5,8,11 * At 12:00 AM, on day 1 of the month, only in February, May, August, and November February, May, August, November. The only way to express a fiscal year that does not begin in January: a step cannot be offset.
• 0 9 1 */3 * At 09:00 AM, on day 1 of the month, every 3 months The same quarters at 09:00. A report that four people are waiting for should not run while all four are asleep.