session expires not in the expected time in node.js

Question

I'm pretty new to Node.js and Express-session. I have created a login/registration system, whenever the user logs in redirected to a page called scoreboard.

Problem: Session expires very soon, not the value that I have set it. I don't know how to fix it?

server.js

var session = require('express-session');
app.use(session({
    secret: "ILoveMostafa",
    resave: false,
    saveUninitialized: false,
    cookie: {
    expires: new Date(Date.now() + 43200)
    }
}))

user.js

router.post('/login', (req, res) => {
    var email = req.body.email;
    var password = req.body.password;
    userModel.authenticate(email, password, (err, user) => {
        if (err) {
            console.log(err)
        }
        else if (!user) {
            console.log('Wrong Password')
        }
        else {
            req.session.userId = user._id;
            res.redirect('/user/scoreboard')
        }
    })
});

router.get('/scoreboard',async (req, res) => {
    console.log(req.session.userId)
    if (req.session.userId) {
        const teams = await userModel.find({}).sort('-score')
        const faculties = await userModel.aggregate([{
            "$group": {
                _id: "$faculty",
                average: {
                    $avg: "$score"
                }
            }
        }]).sort("-average")
        res.render('main/scoreboard', {
            teamInformation: teams,
            finalResult: faculties
        })
    }
    else {
        res.redirect('/')
    }
});

After about 2 minutes when I refresh the page, I redirected to login page!

Answer 1

Date time is measured in milliseconds.

expires: new Date(Date.now() + 43200) is setting the expire time to be 43.2 seconds later than the present time.