package.json

{
  "name": "HelloWorld",
  "author": "Oscar Cortez",
  "version": "0.0.1",
  "description": "Agenda Sample Application",
  "dependencies": {
    "agenda": "*"
   },
  "engine": "node 0.10.x"
}

server.js

Agenda = require('agenda');

var agenda = new Agenda({db: {address: 'localhost:27017/agenda-example'}});

agenda.define('greet the world', function(job, done) {
  console.log(job.attrs.data.time, 'hello world!');
  done();
});

agenda.schedule('in 10 seconds', 'greet the world', {time: new Date()});
agenda.start();

console.log('Wait 10 seconds...');

bad
Agenda = require('agenda');

Good
var Agenda = require('agenda');

👍