Limits of Svelte Context API for Locale Propagation

Goal

Determine how to propagate and reactively update locale and time‑zone information across nested Svelte components.

Constraints

• setContext values are immutable after the first render.
• Intl.DateTimeFormat requires explicit timeZone options.
• No built‑in Svelte utility for automatic time‑zone conversion.

Uncertainty

Is there a supported pattern to make context values reactive, or should developers rely on stores for locale/time‑zone changes? Does Svelte plan to expose a reactive locale store in future releases?

Questions

1. Can the context value be updated post‑render to trigger reactivity in child components, or is a new context required?
2. What are the recommended patterns for synchronizing a global time‑zone setting with the browser’s clock within Svelte?
3. Is there any proposal or roadmap entry for a built‑in reactive locale or time‑zone store in Svelte?