4.4.user.js

// ==UserScript==
// @name         4.4
// @namespace    https://longwoo.me
// @version      0.2.0
// @description  全网默哀模式
// @author       long.woo
// @include      *
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const now = new Date();
    const year = now.getFullYear();
    const month = now.getMonth();
    const date = now.getDate();
    const time = new Date(year, month, date).getTime();
    const yearShort = year.toString().slice(2); // 获取年份后两位
    const chunFen = Math.round(yearShort * 0.2422 + 20.646 - yearShort / 4);
    const qingMing = new Date(year, 2, chunFen).getTime() + 15 * 24 * 60 * 60 * 1000;
    
    if(time !== qingMing) return;
    
    document.getElementsByTagName('html')[0].style = '-webkit-filter: grayscale(100%); filter: grayscale(100%);';
})();