Run Once Monthly at 3 PM

cron expression AWS

$ 0 15 1 * ? *

→

Once a month, on the first day at 3 PM

Minute

Hour

Day of Month

Month

Day of Week

Year

* In a Nutshell

The cron expression 0 15 1 * ? * runs Once a month, on the first day at 3 PM. Monthly cadences are crucial for tasks that don't require high frequency but are critical for business operations. This includes generating end-of-month financial reports, performing system-wide maintenance, or triggering annual compliance checks, ensuring these essential processes execute reliably without manual intervention.

* When to use this

Use 0 15 1 * ? * when a recurring task needs to run Once a month, on the first day at 3 PM. This schedule is commonly associated with end of month and monthly schedules and report generation workloads. It uses AWS EventBridge (6 Fields) syntax, supported by Unix cron daemons, cloud schedulers such as AWS EventBridge, and container orchestration platforms such as Kubernetes CronJob.

CronBase parses 0 15 1 * ? * using a dialect-aware rules engine that identifies the AWS EventBridge (6 Fields) format, validates field structure against the AWS EventBridge (6 Fields) specification, and produces the translation above. Next run times are calculated by forward-scanning from the current UTC clock. Learn how CronBase works.

Platform Implementations

Bash

Prerequisites

Unix/Linux host with a cron daemon running (vixie-cron, cronie, or systemd-cron). The script at /usr/local/bin/run-task.sh must exist and be executable (chmod +x).

Configuration

Run crontab -e to open the crontab editor. Cron reads the server's local timezone; prefix with CRON_TZ=UTC before the expression to pin to UTC. Always redirect output with >> /var/log/cron-tasks.log 2>&1 to capture both stdout and stderr.

Gotchas

Cron jobs inherit a minimal PATH — use full binary paths or set PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin at the top of the crontab. For sub-hourly schedules, add flock -n /tmp/run-task.lock before the command to skip overlapping runs if the previous execution is still running.

bash

# Add to crontab with: crontab -e
0 15 1 * * /usr/local/bin/run-task.sh >> /var/log/cron-tasks.log 2>&1

Last verified: May 11, 2026

Nodejs

Prerequisites

Node.js 18+ with node-cron installed (npm install node-cron). Add "type": "module" to package.json to use the import syntax shown above.

Configuration

Pass { timezone: 'UTC' } as the third argument to cron.schedule(). Without this option the schedule uses the Node.js process timezone, which shifts during DST transitions when servers are not pinned to UTC.

Gotchas

node-cron uses standard 5-field cron syntax — not Quartz 6-field. If your job runs longer than the schedule interval the next trigger fires while the previous is still executing. Use a boolean guard or a queue to skip concurrent runs rather than relying on the scheduler to enforce it.

nodejs

import cron from 'node-cron';

cron.schedule('0 15 1 * *', async () => {
  console.log('[cron] running at', new Date().toISOString());
  // your task logic here
}, { timezone: 'UTC' });

Last verified: May 11, 2026

Python

Prerequisites

Python 3.8+ with apscheduler installed (pip install apscheduler). For Python 3.12+ use apscheduler>=3.10.

Configuration

CronTrigger.from_crontab() accepts a standard 5-field cron string. Always pass timezone='UTC' to both the BlockingScheduler constructor and the trigger to ensure consistent scheduling regardless of the server's locale.

Gotchas

BlockingScheduler.start() blocks the calling thread indefinitely. For a web application, use BackgroundScheduler instead and call scheduler.start() at application startup. APScheduler logs missed fires if the process is stopped and restarted — configure misfire_grace_time (in seconds) to control how late a missed job is allowed to run.

python

from apscheduler.schedulers.blocking import BlockingScheduler
from apscheduler.triggers.cron import CronTrigger

scheduler = BlockingScheduler(timezone='UTC')

@scheduler.scheduled_job(
    CronTrigger.from_crontab('0 15 1 * *', timezone='UTC')
)
def run_task() -> None:
    print('task running')
    # your task logic here

scheduler.start()

Last verified: May 11, 2026

Golang

Prerequisites

Go 1.18+ and github.com/robfig/cron/v3 (go get github.com/robfig/cron/v3).

Configuration

Always create the scheduler with cron.New(cron.WithLocation(time.UTC)). Without WithLocation, the library defaults to the server's local timezone. Call c.Start() to begin the scheduler, then block with select {} to keep the process alive.

Gotchas

robfig/cron v3 uses standard 5-field cron expressions by default. To add second-level precision (6 fields), pass cron.WithSeconds() to cron.New() — but this changes field positions, so never mix syntaxes in the same scheduler. Always check the error returned by c.AddFunc() — a malformed expression is silently ignored without it.

golang

package main

import (
	"fmt"
	"time"

	"github.com/robfig/cron/v3"
)

func main() {
	c := cron.New(cron.WithLocation(time.UTC))
	_, err := c.AddFunc("0 15 1 * *", func() {
		fmt.Println("task running at", time.Now().UTC())
		// your task logic here
	})
	if err != nil {
		panic(err)
	}
	c.Start()
	defer c.Stop()
	select {}
}

Last verified: May 11, 2026

Java

Prerequisites

Spring Boot 2.7+ (or Spring Framework 5.3+) with spring-context on the classpath. Annotate your @SpringBootApplication class with @EnableScheduling — without it, @Scheduled methods are silently ignored.

Configuration

Spring @Scheduled uses a 6-field Quartz-style expression: [sec] [min] [hr] [dom] [mon] [dow]. The expression 0 0 15 1 * ? is derived from 0 15 1 * ? * — a leading 0 is prepended for the seconds field, and ? replaces the unconstrained day field.

Gotchas

Standard Unix cron has 5 fields; Spring requires 6. Pasting a 5-field expression directly into @Scheduled shifts every field by one and the job misfires silently. Use ? for either dom or dow — Quartz does not allow both to be *.

java

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class ScheduledTask {

    @Scheduled(cron = "0 0 15 1 * ?")
    public void runTask() {
        System.out.println("task running at: " + java.time.Instant.now());
        // your task logic here
    }
}

Last verified: May 11, 2026

Kubernetes

Prerequisites

Kubernetes 1.21+ (CronJob API is GA). kubectl configured with cluster access. Container image must be pullable from within the cluster.

Configuration

Apply with kubectl apply -f cronjob.yaml. Check status with kubectl get cronjobs and inspect run history with kubectl get jobs. concurrencyPolicy: Allow is set because this schedule fires infrequently — parallel runs are acceptable.

Gotchas

Without startingDeadlineSeconds, a missed job (e.g., due to cluster downtime) triggers as soon as the controller recovers. Kubernetes 1.25+ supports timeZone: UTC in the spec to avoid timezone ambiguity. Keep successfulJobsHistoryLimit and failedJobsHistoryLimit low to avoid accumulating stale Job objects in the cluster.

kubernetes

apiVersion: batch/v1
kind: CronJob
metadata:
  name: scheduled-task
spec:
  schedule: "0 15 1 * *"
  concurrencyPolicy: Allow
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
          - name: task
            image: alpine:3.19
            command: ["/bin/sh", "-c", "echo 'task running'"]

Last verified: May 11, 2026

Frequently Asked Questions

What specific task does the `0 15 1 * ? *` schedule run?

This schedule is configured to execute a task once per month, specifically on the first day of the month at 3:00 PM. It's designed for tasks that need to happen monthly but not daily or hourly.

How does this schedule handle time zones and daylight saving changes?

Cron schedules operate based on the time zone configured for the system running the cron job. During daylight saving time transitions, the exact execution time might shift by an hour, so it's important to test and confirm behavior.

How can I verify that my task ran successfully with this schedule?

You can verify task execution by checking the logs generated by the task itself, monitoring application metrics for expected activity, or setting up notifications that confirm successful completion. Confirming the task's output is also a good validation step.

What potential issues should I be aware of with this schedule?

A potential issue with monthly schedules is related to the varying number of days in months and potential conflicts around month-end processing if your task has dependencies on other systems that also run at month-end.

What is a common variation or alternative to this schedule?

A common variation might involve running a task more frequently, such as daily at the same time, or perhaps weekly on a specific day. Adjusting the schedule depends on the actual business need for task frequency.