Cron scheduling for node.
npm install node-cronjob
var cron = require('node-cronjob');
cron.schedule(this, "0 0 * * *", function() { // once per day at midnight. Minute = 0, hour = 0
log.debug("Mmmm, cronjobs".);
});
The 2nd parameter is a cron-like string, see here http://en.wikipedia.org/wiki/Cron#Examples