Optimal twitter post time

optitwitter.js

var fs = require('fs');
var http = require('http');
var _ = require('underscore');

function getTimeline(screen_name, callback) {

    //Create an array with one array for each hour of the week
    var hours = [];
    _.each(_.range(168), function(hour) {
        hours.push([]);
    });

    http.get('http://api.twitter.com/1/statuses/user_timeline.json?count=200&screen_name=' + screen_name, function(res) {

        var all_tweets = JSON.parse(res);
        _.each(all_tweets, function(tweet) {
            var d = new Date(tweet.created_at);
            var hour = (d.getDay() * 24) + d.getHours();
            hours[hour].push(tweet);
        });
        var data = _.map(hours, function(tweets, num) {
            var retweets = 0;
            retweets += (parseInt(_.pluck(tweets, 'retweet_count'), 10) || 0);
            return {
                retweets: retweets,
                total_tweets: tweets.length,
                hour: num
            };
        });
        callback(null, data);
    })
}

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