data.json

{
 "paycheck": {
  "date": "12/30/2016",
  "pay": 0.0
 }
}

test.js

var casper = require('casper').create();
var xpath = require("casper").selectXPath;

var config = require('../config.json');
var data = require('../data.json');
var fs =require('fs');

var current={
  "work":{},
};

var hourly =config.money.hourly;

casper.start(hourly.url,function () {
  this.wait(2000,function () {
    this.echo('filling form...');
    this.sendKeys('#username',config.cas.username);
    this.sendKeys('#password',config.cas.password);
    // this.capture('username.png');
    this.click('input[name="_eventId_submit"]');
    this.wait(3000,function () {
      // this.echo("taking a screenshot");
      // this.capture('currentstate.png');
      current.work.hours=parseFloat((this.fetchText(xpath("//div[@id='timesheet-table-basic']/table/tbody/tr[4]/td[18]"))));
      // this.echo("hours worked is: "+current.hours);
      // this.echo("money earned: $"+ current.hours*hourly.rate);
      current.work.amount=current.work.hours*hourly.rate;
        var temp =JSON.parse(JSON.stringify(data));
        current.push(temp);
        console.log("output: " + JSON.stringify(current,null,' '));
        fs.write('data.json',JSON.stringify(current,null,' '),'w');
    });// end of second wait

  });// end of first wait function

});//end of start