if(date.getFullYear() <= 2017) {
    if(date.getMonth() <= 11) {
        if(date.getDate() <= 26) {
            if(date.getHours() <= 23) {
                if(date.getMinutes() <= 59) {
                    if(date.getSeconds() <= 59) {
                        //Display popup before 2017-11-27
                    }
                }
            }
        }
    }
}