Excited about this, we've been working on the upcoming Container Timing API. Want to learn more? Take a read of the blog post below, put together with @tunetheweb.com and @jdapena.bsky.social. Feedback is very welcome. Try it out and help us shape this API! [This feature is Mozilla Approved]
Barry Pollard@tunetheweb.com · 3mo agoThere's a new #webperf measurement API in the works! Check out this post looking at the work @jason-williams.co.uk and @jdapena.bsky.social have been putting into there Container Timing—available as an origin trail from Chrome 148 (rolling out next week). developer.chrome.com/blog/contain...
![Code example showing the usage of Temporal.ZoneddateTime
```js
// London DST starts: 2026-03-29 01:00 -> 02:00
const zdt = Temporal.ZonedDateTime.from(
"2026-03-29T00:30:00+00:00[Europe/London]",
);
console.log(zdt.toString());
// → "2026-03-29T00:30:00+00:00[Europe/London]"
const plus1h = zdt.add({ hours: 1 });
console.log(plus1h.toString());
// "2026-03-29T02:30:00+01:00[Europe/London]" (01:30 doesn't exist)
```](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:r5emt2gkdrkb2yc6y7xndxpe/bafkreicgonzisednk3qegophndqf6fnslwtvbd7gshsgtv6fpi3arh2dsi)
