HTTPfy

Every 4 hours

At 00:00, 04:00, 08:00, 12:00, 16:00 and 20:00: 6 runs a day.

0 */4 * * * Open in Crontab Generator
2,190runs in the next 365 days
42runs per week
4 hoursbetween every run
04:00next run, Wed 11 Nov UTC

What it is used for

Refreshing reports, rotating logs on busy hosts and syncing reference data.

Field by field

FieldValueMatches
Minute00
Hour*/40, 4, 8, 12, 16, 20
Day of month*every value
Month*every value
Day of week*every value
 
0 */4 * * * /path/to/job

Next 10 run times

Computed when this page loaded (2026-11-11 02:24 UTC), assuming the scheduler runs in UTC.

#UTCYour local time
1Wed 2026-11-11 04:00
2Wed 2026-11-11 08:00
3Wed 2026-11-11 12:00
4Wed 2026-11-11 16:00
5Wed 2026-11-11 20:00
6Thu 2026-11-12 00:00
7Thu 2026-11-12 04:00
8Thu 2026-11-12 08:00
9Thu 2026-11-12 12:00
10Thu 2026-11-12 16:00

Things to watch with this schedule

  • 4 divides 24, so runs are evenly spaced including across midnight.

Kubernetes CronJob

Kubernetes uses the same five fields. Set spec.timeZone (stable since Kubernetes 1.27), otherwise the schedule follows the time zone of kube-controller-manager.

apiVersion: batch/v1
kind: CronJob
metadata:
  name: every-4-hours
spec:
  schedule: "0 */4 * * *"
  timeZone: "Etc/UTC"
  concurrencyPolicy: Forbid
  startingDeadlineSeconds: 300
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
            - name: job
              image: debian:bookworm-slim
              command: ["/bin/sh", "-c", "/app/run-job.sh"]

GitHub Actions

Workflow schedules use five-field cron in UTC and run only from the default branch. Runs at minute 0 are the most likely to be delayed or dropped when GitHub is busy; an odd minute such as 7 or 23 starts more reliably.

on:
  schedule:
    - cron: '0 */4 * * *'   # UTC

jobs:
  run:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: ./run-job.sh

systemd timer

The equivalent OnCalendar= value is *-*-* 00/4:00:00. Check it with systemd-analyze calendar '*-*-* 00/4:00:00', which prints the next elapse time. Persistent=true runs a missed job after downtime, which classic cron never does.

[Unit]
Description=Every 4 hours

[Timer]
OnCalendar=*-*-* 00/4:00:00
Persistent=true

[Install]
WantedBy=timers.target

AWS EventBridge

EventBridge rules take six fields (minute, hour, day-of-month, month, day-of-week, year) in UTC; EventBridge Scheduler can use a time zone. One of day-of-month and day-of-week must be ?, and day-of-week runs 1-7 from Sunday, so names are used here.

cron(0 0/4 * * ? *)

Quartz Scheduler (Java)

Quartz adds a leading seconds field and needs ? in either day field; days of the week are 1 (SUN) to 7 (SAT).

0 0 0/4 * * ?

Spring's @Scheduled(cron = ...) also uses six fields, but numbers days of the week 0-7 with Sunday as 0 or 7, like Unix cron; the names shown above work in both.

Related schedules