Cron Expression: every 15 hours

Detailed explanation and examples for this cron schedule pattern

Cron Format Examples

Standard UNIX (5 fields)

0 */15 * * *
minute hour day-of-month month day-of-week

Quartz (6 fields)

0 0 */15 * * ?
second minute hour day-of-month month day-of-week

Quartz with Year (7 fields)

0 0 */15 * * ? *
second minute hour day-of-month month day-of-week year

Cron Expression with Names

0 */15 * * *
Using month and day-of-week names where applicable

System Examples

Common Systems

Linux Crontab

0 */15 * * * /path/to/command

GitHub Actions

cron: '0 */15 * * *'

Cloud Providers

AWS CloudWatch

cron(0 \*/15 \* \* \*)

Google Cloud Scheduler

0 */15 * * *

Azure Functions

"schedule": "0 */15 * * *"

DigitalOcean App Platform

cron: '0 */15 * * *'

Container Orchestration

Kubernetes CronJob

schedule: "0 */15 * * *"

Docker Swarm

placement: { constraints: [node.role == manager] }
labels: { cron: "0 */15 * * *" }

Programming Languages

Quartz (Java)

CronScheduleBuilder.cronSchedule("0 */15 * * *")

Node.js (node-cron)

cron.schedule('0 */15 * * *', function() { // Your code here });

Python (python-crontab)

from crontab import CronTab cron = CronTab(user='username') job = cron.new(command='/path/to/command') job.setall('0 */15 * * *')

PHP (Symfony)

# config/packages/messenger.yaml framework: messenger: transports: cron: '%env(MESSENGER_TRANSPORT_DSN)%' options: cron_expression: '0 */15 * * *'

Expression Breakdown

Standard Unix Format (5 fields)

This cron expression is composed of 5 time/date fields:

FieldValueDescription
Minute00
Hour*/15Every 15 hours (0-23)
Day of Month*Every day of the month (1-31)
Month*Every month (1-12)
Day of Week*Every day of the week (0-6, where 0 is Sunday)

Quartz Format (6 fields)

In Quartz, we add a seconds field (and can replace * with ? in day-of-week):

FieldValueDescription
Second00
Minute00
Hour*/15Every 15 hours (0-23)
Day of Month*Every day of the month (1-31)
Month*Every month (1-12)
Day of Week?Any value (no specific value)

AWS CloudWatch Format (6/7 fields)

AWS CloudWatch Events adds an optional year field:

FieldValueDescription
Minute00
Hour*/15Every 15 hours (0-23)
Day of Month*Every day of the month (1-31)
Month*Every month (1-12)
Day of Week*Every day of the week (0-6, where 0 is Sunday)
Year (Optional)*Every year

Format Differences

Note that different systems interpret cron expressions slightly differently. The standard Unix format has 5 fields, while Quartz and AWS formats have additional fields. Some special characters like ?, L, W, and # are only supported in specific implementations.

Execution Frequency

This job runs every 15 hours