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Dhiraj kumar Nayak
Dhiraj kumar Nayak

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Task Scheduler in Node app

Install cron job npm in your project

you have to install cron on your nodejs application
you can install the cron by
npm install cron

Use cron On your project

var CronJob = require('cron').CronJob;
var job = new CronJob('* * * * * *', function() {
  console.log('You will see this message every second');
}, null, true, 'America/Los_Angeles');
job.start();

cron vlaue range

Name Required Allowed Values Allowed Special
Seconds Y 0-59 , - * /.
Minutes Y 0-59 , - * /
Hours Y 0-23 , - * /
Day of month Y 1-31 , - * ? / L W C
Month Y 0-11 or JAN-DEC , - * /
Day of week Y 1-7 or SUN-SAT , - * ? / L C #
Year N empty or 1970-2099 , - * /

these value are going to use use in the cron job

Some example of creating cron

Expression Means
0 0 12 * * ? Fire at 12:00 PM (noon) every day
0 15 10 ? * * Fire at 10:15 AM every day
0 15 10 * * ? Fire at 10:15 AM every day
0 15 10 * * ? * Fire at 10:15 AM every day
0 15 10 * * ? 2005 Fire at 10:15 AM every day during the year 2005
0 * 14 * * ? Fire every minute starting at 2:00 PM and ending at 2:59 PM, every day
0 0/5 14 * * ? Fire every 5 minutes starting at 2:00 PM and ending at 2:55 PM, every day
0 0/5 14,18 * * ? Fire every 5 minutes starting at 2:00 PM and ending at 2:55 PM, AND fire every 5 minutes starting at 6:00 PM and ending at 6:55 PM, every day
0 0-5 14 * * ? Fire every minute starting at 2:00 PM and
0 10,44 14 ? 3 WED Fire at 2:10 PM and at 2:44 PM every Wednesday in the month of March
0 15 10 ? * MON-FRI Fire at 10:15 AM every Monday, Tuesday, Wednesday, Thursday and Friday
0 15 10 15 * ? Fire at 10:15 AM on the 15th day of every month
0 15 10 L * ? Fire at 10:15 AM on the last day of every month
0 15 10 ? * 6L Fire at 10:15 AM on the last Friday of every month
0 15 10 ? * 6L Fire at 10:15 AM on the last Friday of every month
0 15 10 ? * 6L 2002-2005 Fire at 10:15 AM on every last friday of every month during the years 2002, 2003, 2004, and 2005
0 15 10 ? * 6#3 Fire at 10:15 AM on the third Friday of every month
0 0 12 1/5 * ? Fire at 12 PM (noon) every 5 days every month, starting on the first day of the month
0 11 11 11 11 ? Fire every November 11 at 11:11 AM

Use cases

there are total 7 corn fields but the year field is optional. You need to fill atleast 6 cron field to execute.

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