Temporal: The 9-Year Journey to Fix Time in JavaScript
Published on 11 March 2026
Welcome to our blog! I'm Jason Williams, a senior software engineer on Bloomberg's JavaScript Infrastructure and Terminal Experience team. Today the Bloomberg Terminal runs a lot of JavaScript. Our team provides a JavaScript environment to engineers across the company.
Bloomberg may not be the first company you think of when discussing JavaScript. It certainly wasn't for me in 2018 before I worked here. Back then, I attended my first TC39 meeting in London, only to meet some Bloomberg engineers who were there discussing Realms, WebAssembly, Class Fields, and other topics. The company has now been involved with JavaScript standardization for numerous years, including partnering with Igalia. Some of the proposals we have assisted include Arrow Functions, Async Await, BigInt, Class Fields, Promise.allSettled, Promise.withResolvers, WeakRefs, standardizing Source Maps, and more!
The first proposal I worked on was Promise.allSettled, which was fulfilling. After that finished, I decided to help out on a proposal around dates and times, called Temporal.
How Does JavaScript Change? #
JavaScript is unique in that it runs in all browsers. There is no single "owner," so you can't just make a change in isolation and expect it to apply everywhere. You need buy-in from all parties. Evolution happens through TC39, the Technical Committee responsible for ECMAScript.
Proposals move through a series of maturity stages:
Stage 0 - Idea
Stage 1 - Problem space accepted
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