Creates a glitch in the Matrix in your GitHub profile ;-)

calendar-graph-hack.js

// ==UserScript==
// @name         Calender Graph Hack
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Just for fun
// @author       Mario Stöcklein (https://github.com/mstoecklein)
// @match        https://github.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=github.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const matrix = document.querySelectorAll('.js-calendar-graph-svg>g>g');

    if (!matrix) {return}
    const cols = Array.from(matrix).slice(0, 52);
    let lastTS = null
    function update(timestamp) {
        if (lastTS + 60 > timestamp) {
            requestAnimationFrame(update);
            return;
        }

        // move down and fade old position
        for (let i = 0; i < cols.length; i++) {
            const rows = cols[i].querySelectorAll('rect');
            const changed = [];
            for (let j = 0; j < rows.length; j++) {
                if (!changed.includes(j)) {
                    const level = parseInt(rows[j].getAttribute('data-level'), 10);
                    rows[j].setAttribute('data-level', level > 0 ? level - 1 : 0);
                    if (level === 4 && rows.length > j + 1) {
                        rows[j + 1].setAttribute('data-level', level > 0 ? level : 0);
                        if (level > 0) {
                            changed.push(j + 1);
                        }
                    }
                }
            }
        }

        const started = [];
        do {
            const i = Math.round(Math.random() * (cols.length - 1));
            if (!started.includes(i)) {
                cols[i].querySelector('rect').setAttribute('data-level', 4);
                started.push(i);
            }
        } while(started.length === 25)

            lastTS = timestamp;
        requestAnimationFrame(update);
    }
    update();
})();