cal.js

// ==UserScript==
// @name         Google Calendar Auto-Click Today
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Clicks the "Today" button on Google Calendar every 10 minutes and refreshes at midnight
// @match        https://calendar.google.com/*
// @grant        none
// ==/UserScript==

(function () {
  "use strict";

  function clickTodayButton() {
    const xpath = "//button[span[text()='Today']]";
    const result = document.evaluate(
      xpath,
      document,
      null,
      XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
      null,
    );
    const matchingButtons = [];
    for (let i = 0; i < result.snapshotLength; i++) {
      matchingButtons.push(result.snapshotItem(i));
    }
    if (matchingButtons.length > 0) {
      matchingButtons[0].click();
    }
  }

  function scheduleMidnightRefresh() {
    const now = new Date();
    const midnight = new Date(
      now.getFullYear(),
      now.getMonth(),
      now.getDate() + 1, // next day
      0, 0, 0, 0,        // 00:00:00.000
    );
    const msUntilMidnight = midnight - now;

    setTimeout(function () {
      location.reload();
    }, msUntilMidnight);
  }

  // Run once on page load (after a short delay to let the UI render)
  setTimeout(clickTodayButton, 3000);

  // Then run every 10 minutes (600,000 ms)
  setInterval(clickTodayButton, 10 * 60 * 1000);

  // Schedule a full page refresh at midnight
  scheduleMidnightRefresh();
})();