index.js

'use strict'

var request = require('request')
var cheerio = require('cheerio')

function fetch(day, month, lang, events) {
  return new Promise(function(resolve) {
    var events = []
    var metadata = []
    request(`https://${lang}.wikipedia.org/wiki/${day}_de_${month}`, function (error, response, html) {
      if (!error && response.statusCode == 200) {
        var $ = cheerio.load(html)
        var li = $('div#toc.toc').next().next().next().children()

        $(li).each(function(i, element){

          let date = $(this).children().html()
          let data = $(this).children().parent().text().slice(2)

          if (!isNaN(parseInt(date))) {
            let scraped = {
              date: parseInt(date),
              data: capitalizeFirstLetter(data)
            }
		  	metadata.push(scraped)
          }
        })

        Promise.resolve(metadata)
      }
    })
  })
}

var lastDay = getLastDayOfMonth(2016)

var month = 6 // meterlo en for luego
var events = []
for (var day = 1; day <= 2; day++) {
 fetch(day, 'julio', 'es', events).then(function(res) {
  console.log(res)
 })
}

// Utils
function capitalizeFirstLetter(string) {
  return string.charAt(0).toUpperCase() + string.slice(1);
}

function getLastDayOfMonth(year) {
  var lastDay = []
  for (var month = 1; month <= 12; month++) {
    lastDay[month] = new Date(year, month, 0).getDate();
  }

  return lastDay
}