How to set up a cron job that runs a Node.js app

To run a Node.js app on a schedule, wrap it in a small shell script and register that script with crontab. Cron, the scheduler built into Linux and macOS, will then run it for you, every day, every hour, whatever you need.

I use this for things like sending a daily report email or cleaning up old records in a database.

Create the script

Create a shell script in a file, for example called run.sh:

#!/bin/sh
node app.js

Give it execution rights:

chmod +x run.sh

You could put the node command directly in the crontab, but I prefer the script. It gives you one place to add more steps later, like setting environment variables, without touching cron again.

Register the cron job

Then run:

crontab -e

By default this opens with the default editor, which is usually vim.

| Tip if you’re new to vim: use i to enter insertion mode, so you can type/paste, then esc and wq to save and quit.

Now you can add one line for each cron job.

The syntax to define cron jobs is kind of scary. A line has 5 time fields, in this order: minute, hour, day of month, month, day of week. A * means “every”. This is why I usually use a website to help me generate it without errors: https://crontab-generator.org/

I also built my own free cron builder that translates the expression to plain English and shows the next runs.

You pick a time interval for the cron job, and you type the command to execute.

I chose to run this every day at 10AM.

This is the crontab line I need to run:

0 10 * * * /Users/flaviocopes/dev/run.sh >/dev/null 2>&1

Reading the fields: minute 0, hour 10, every day of the month, every month, every day of the week.

The >/dev/null 2>&1 part discards everything the script prints. If you’d rather keep the output, send it to a log file instead:

0 10 * * * /Users/flaviocopes/dev/run.sh >> /Users/flaviocopes/dev/cron.log 2>&1

If all goes well, the cron job is set up.

Check and remove jobs

Once this is done, you can see the list of active cron jobs by running:

crontab -l

You can remove a cron job running crontab -e again, removing the line and exiting the editor.

What if the job doesn’t run?

The most common problem: the script works when you run it by hand, but does nothing under cron.

Cron runs your script with a minimal environment, not your shell environment. Your PATH is mostly empty, so node might not be found, especially if you installed it with a version manager.

The fix is to use absolute paths in the script. Find where Node lives with which node, then:

#!/bin/sh
cd /Users/flaviocopes/dev
/usr/local/bin/node app.js

The cd matters too. Cron doesn’t start in your project folder, so a relative path like app.js would fail without it.