Laravel carbon wrong timezone

I have a laravel 5.2 app with authentication.I have built a custom global middleware that updates a "last_seen" column on the users table for each user.

Note: It is a middleware that runs after the request.

I use the "UTC" timezone so that there would be no errors when calculating the difference anywhere in the world.

Everything works fine and as expected,until i log out.When I log out,the column is updated with the time in my current timezone "romania". I have no idea why that is,since I never declared a timezone other than "UTC".

Here is my middleware code:

<?php

namespace App\Http\Middleware;

use Auth;
use Closure;
use Carbon\Carbon;

class LastSeenMiddleware
{
    public function handle($request, Closure $next)
    {
        $response = $next($request);

        if(Auth::check()){
            Auth::user()->last_seen = Carbon::now();
            Auth::user()->save();
        }

        return $response;
    }
}

via Chebli Mohamed