function isDateInRange(danPer, documentDate) {
    var danPerDate = new Date(danPer.slice(0, 4), Number(danPer.slice(4, 6)) - 1, 0, 0, 0, 0, 0),
        docDate = new Date(documentDate.slice(6, 10), Number(documentDate.slice(3, 5)) - 1, 0, 0, 0, 0, 0);
    if (docDate.setMonth(docDate.getMonth() + 12) < danPerDate.valueOf()) {
        return false;
    } else {
        return true;
    }
}