How to easily create CRON Expression for Scheduling a Apex Job in Salesforce

CRON Maker:

         While scheduling a apex job in Developer Console you need to create a CRON expression, then schedule a job with the created expression like below,

scheduledMerge m = new scheduledMerge();
String sch = '20 30 8 10 2 ?';
String jobID = system.schedule('Merge Job', sch, m);

There is a one website available to make your CRON expression easily,

URL: http://www.cronmaker.com/