app.js

//http://stackoverflow.com/questions/10639914/is-there-a-way-to-get-bings-photo-of-the-day

var fs = require('fs')
var path = require('path')

var request = require('request')

function fetch(){
  var uri = 'http://www.bing.com/HPImageArchive.aspx?format=js&idx=0&n=1'

  request(uri, function(error, response, body){
    try {
      var data = JSON.parse(body)
      var images = data.images

      var pictures = path.join(__dirname, '../../Pictures/bing-wallpapers/')

      images.forEach(function(image){
        var ext = path.extname(image.url).split('&')[0]
        var img = path.join(pictures, image.fullstartdate + ext)

        if (!fs.existsSync(img)) {
          request(`https://www.bing.com${image.url}`).pipe(
            fs.createWriteStream(img)
          )
        } else {
          console.log('already exists')
        }
      })
    } catch (e) {
      console.error(e)
    }
  })
}

fetch()