site/js/pride-logo.js

(function () {
  var month = Number(
    new Intl.DateTimeFormat("de-DE", {
      timeZone: "Europe/Berlin",
      month: "numeric"
    }).format(new Date())
  );

  if (month !== 6) {
    return;
  }

  document.querySelectorAll("img[data-pride-src]").forEach(function (img) {
    img.src = img.getAttribute("data-pride-src");
  });
})();