code: function resolveDate (base_url, input, callback) {
  
    var date = input;
  
    // If provided a date string
    if ((typeof input == "string" || typeof input == "number") && input !== "latest") {
      date = new Date(input);
    }
  
    // If provided a date object
    if (moment.isDate(date)) { return callback(null, date); }
  
    // If provided "latest"
    else if (input === "latest") {
      var latest = base_url + '/latest.json';
      request({
        method: 'GET',
        uri: latest,
        timeout: 30000
      }, function (err, res) {
        if (err) return callback(err);
        try { date = new Date(JSON.parse(res.body).date); }
        catch (e) { date = new Date(); }
        return callback(null, date);
      });
    }
  
    // Invalid string provided, return new Date
    else { return callback(null, new Date()); }
  }
docs: Takes an input, either a date object, a date timestamp, or the string "latest"
  and resolves to a native Date object.
  @param  {String|Date}   input    The incoming date or the string "latest"
  @param  {Function} callback The function to be called when date is resolved