function pageGray(beginTime, endTime) {
var now = new Date().getTime();
if (now >= new Date(beginTime.replace(/\-/g, '/')).getTime() && now <= new Date(endTime.replace(/\-/g, '/')).getTime()) {
document.getElementsByTagName("html")[0].className += "filter-grey"
} else {
return;
}
}
pageGray('2020/04/04 00:00:00', '2020/04/05 00:00:00');