Run a Job Daily at 1:30 AM | CronBase

cron expression AWS
$ 0 30 1 * ? *

Once a day at 1:30 AM

0
Minute
30
Hour
1
Day of Month
*
Month
?
Day of Week
*
Year

* In a Nutshell

The cron expression 0 30 1 * ? * runs Once a day at 1:30 AM. This cadence is ideal for batch jobs that do not require immediate user interaction, such as overnight data processing, system backups, or report generation. Running at a low-traffic time like 1:30 AM minimizes potential impact on end-users and ensures critical tasks complete before the business day begins.

* When to use this

Use 0 30 1 * ? * when a recurring task needs to run Once a day at 1:30 AM. This schedule is commonly associated with aws eventbridge and daily schedules and database backup 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 30 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 30 1 * * /usr/local/bin/run-task.sh >> /var/log/cron-tasks.log 2>&1

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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 30 1 * *', async () => {
  console.log('[cron] running at', new Date().toISOString());
  // your task logic here
}, { timezone: 'UTC' });

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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 30 1 * *', timezone='UTC')
)
def run_task() -> None:
    print('task running')
    # your task logic here

scheduler.start()

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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 30 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 {}
}

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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 30 1 * ? is derived from 0 30 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 30 1 * ?")
    public void runTask() {
        System.out.println("task running at: " + java.time.Instant.now());
        // your task logic here
    }
}

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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 30 1 * *"
  concurrencyPolicy: Allow
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
          - name: task
            image: alpine:3.19
            command: ["/bin/sh", "-c", "echo 'task running'"]

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Frequently Asked Questions

What does the '0 30 1 * ? *' cron schedule do?

The `0 30 1 * ? *` cron schedule triggers a job to run exactly once every day at one thirty in the morning. It's designed for tasks that need to occur once within a 24-hour period, typically during off-peak hours.

How does this schedule handle time zones and Daylight Saving Time?

Cron schedules operate based on the time zone settings of the environment where they are executed. It is important to be aware of the specific time zone configuration to ensure the job runs at the intended local time, especially during Daylight Saving Time transitions.

How can I verify that my job is running according to the schedule?

You can verify the job's execution by checking your system's logs for entries indicating the start and end of the task. Additionally, monitoring tools can be configured to alert you if the job starts or finishes within the expected time frame.

What are potential issues with a daily early morning schedule?

A potential gotcha is if the job takes longer than an hour to complete; it could run into the next hour's schedule. Ensure your job's runtime is accounted for, or consider extending the schedule's execution window if necessary.

What is a common variation for this daily schedule?

A common variation is to run the job slightly later, perhaps at 2:30 AM, to avoid any potential overlap with other overnight processes that might still be concluding. This allows for a larger buffer and reduces the risk of conflicts.

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