JSFiddle - React, Tailwind, and code Playground

JavaScript

// Store date upon creation of session.
var session = {}, sessions = [];
session.time = Date.now()
sessions.push(session);

function updateSessions()
{
    for (var i=sessions.length-1; i >= 0; --i)
    {  
        var session = sessions[i];

        // Check if day or more is elapsed.
        if (session.time <= Date.now() - (60000*24))
        {
            sessions.splice(i, 1);
            alert("session "+i+" removed.");
        }
    }
  
    // Check every hour
    setTimeout(updateSessions, 60000);
}

updateSessions();