Add Cron job in WordPress

I want to create a really simple plugin which will do a cron job,
basically the work of the plugin will be to get the data of a csv file from server and read it and then import the csv data in website.
theres already a plugin named 'Automotive' which we used to create listings on website
so the custom plugin will get csv file data and update the listings information on website.
if you think you can do this then let me know
its urgent