server.js

var express = require("express");
var app = express();

app.use(express.static("public"));
app.set("views", __dirname + "/views");
app.set("view engine", "pug");

function daysInMonth(month) {
  var year = new Date().getFullYear();
  return new Date(year, month, 0).getDate();
}

var months = [
  "Jan",
  "Feb",
  "Mar",
  "Apr",
  "May",
  "Jun",
  "Jul",
  "Aug",
  "Sep",
  "Oct",
  "Nov",
  "Dec",
];
var grid = {};
for (var i = 0; i < months.length; i++) {
  grid[months[i]] = daysInMonth(i + 1);
}

var moodOptions = {
  5: "amazing",
  4: "great",
  3: "average",
  2: "difficult",
  1: "tough",
  0: "none",
};

app.get("/", function (req, res) {
  res.render("index", { grid: grid, moodOptions: moodOptions });
});

var listener = app.listen(process.env.PORT, function () {
  console.log("Your app is listening on port " + listener.address().port);
});