Readiness: Implemented

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Dates and time

@uniflowed/temporal gives an event a precise instant without borrowing the server's or reader's time zone. Decide how to display it later. This keeps a date written by a server in UTC from changing meaning when a browser opens it in another zone.

// @flow
import { Temporal } from "@uniflowed/temporal";

const published = Temporal.Instant.from("2026-09-04T06:00:00Z");
const tokyo = published.toZonedDateTimeISO("Asia/Tokyo");
const day = tokyo.toPlainDate().toString();

The instant is the same event everywhere. tokyo is its wall clock in a chosen zone; day is the calendar date in that zone. Store the instant for a timestamp and choose the zone at the edge where someone reads it. A string without an offset, such as "2026-09-04", is a date rather than an instant.

Render it without a hydration mismatch

Time from @uniflowed/web renders a <time> whose dateTime stays the exact instant. iso, date and zoned use a deterministic zone on server and browser. local and relative begin with that stable text, then update after hydration to the reader's locale or the current time.

// @flow
import { Time } from "@uniflowed/web";

export component PublishedAt() {
  return <Time value="2026-09-04T06:00:00Z" format="zoned" zone="Asia/Tokyo" />;
}

The Web components guide covers the other browser-facing primitives. Use Temporal.Now.instant() when the current clock is the input; tests that need a fixed clock should inject one through uf's render context.

Check which implementation is active

isLite reports whether the host is using uf's ISO 8601 subset or native Temporal. The five core value types and ISO arithmetic are available on both. Non-ISO calendar arithmetic through withCalendar still requires uf's native runtime and raises NativeRuntimeRequiredError in this package. Formatting a date with Intl in another calendar is a different operation and can use the host's locale data.

Edit this pagedocs/app/guide/temporal/$page.mdx