--- title: [RFC] Duration class | daily.dev description: PHP internals discussion thread covering a proposed RFC to introduce a new `Time\Duration` class in PHP 8.6. The class is designed to represent stopwatch-style... canonical: https://daily.dev/posts/rfc-duration-class-1raffhvsp twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: [RFC] Duration class | daily.dev og:description: PHP internals discussion thread covering a proposed RFC to introduce a new `Time\Duration` class in PHP 8.6. The class is designed to represent stopwatch-style... og:url: https://daily.dev/posts/rfc-duration-class-1raffhvsp og:image: https://api.daily.dev/og/posts/1RAfFhvSP.png og:image:alt: [RFC] Duration class og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # [RFC] Duration class **[externals.io](https://daily.dev/sources/externals)** · 96 min read · 0 upvotes · 0 comments ## Summary PHP internals discussion thread covering a proposed RFC to introduce a new `Time\Duration` class in PHP 8.6. The class is designed to represent stopwatch-style durations (not calendar periods) with nanosecond precision, stored internally as a seconds+nanoseconds pair. It targets the new Polling API already in PHP 8.6 and is intended as the first step toward a modernized date/time API. The thread covers design decisions including: why the highest constructor unit is hours while internal representation uses seconds; why ISO 8601 serialization is deferred; why floating-point total methods are excluded for now due to precision concerns; namespace choice (`Time` vs `DateTime`); the `fromIso8601String` method accepting only PT-prefixed period strings; and debate over `add`/`sub` vs a variadic `sum` method. The authors explicitly rejected using the Rust `temporal_rs` library, citing API design complexity and Zend Engine integration challenges. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [\[RFC\] Duration class](https://daily.dev/posts/rfc-duration-class-6uiyzwcpa) · externals.io · 0 upvotes · 0 comments - [\[RFC\] Duration class](https://daily.dev/posts/rfc-duration-class-k3vcw9wkg) · externals.io · 0 upvotes · 0 comments - [\[RFC\] Duration class](https://daily.dev/posts/rfc-duration-class-xax48upgz) · externals.io · 0 upvotes · 0 comments - [\[RFC\] Duration class](https://daily.dev/posts/rfc-duration-class-dnb0xo2se) · externals.io · 0 upvotes · 0 comments - [\[RFC\] Duration class](https://daily.dev/posts/rfc-duration-class-rtajzuwil) · externals.io · 0 upvotes · 0 comments --- Tags: [#architecture](https://daily.dev/tags/architecture), [#php](https://daily.dev/tags/php) [View this post on daily.dev](https://daily.dev/posts/rfc-duration-class-1raffhvsp) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"[RFC] Duration class","url":"https://daily.dev/posts/rfc-duration-class-1raffhvsp","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/rfc-duration-class-1raffhvsp"},"datePublished":"2026-07-01T18:28:46.763Z","dateModified":"2026-07-01T18:29:11.016Z","description":"PHP internals discussion thread covering a proposed RFC to introduce a new `Time\\Duration` class in PHP 8.6. 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