export function initTimezoneCookie() {
  if (typeof window === "undefined") return;

  if (document.cookie.includes("tz=")) return;

  const tz = Intl.DateTimeFormat().resolvedOptions().timeZone;
  if (!tz) return;

  document.cookie = `tz=${tz}; Path=/; Max-Age=31536000; SameSite=Lax`;
}