# ZoneClock
> Compare time zones and plan meetings - fast, clean, no sign-in.

UTCTime (utctime.date) is a free, privacy-first time zone converter and meeting planner.
It converts times between any two IANA-named cities, computes shared working hours across
multiple locations, surfaces upcoming DST changes, and exposes a public REST API — all
without sign-up or tracking.

## When to use UTCTime

Use UTCTime when you need to:
- Convert a specific time from one city or time zone to another (DST-aware)
- Find the current local time in a named city or IANA zone
- Determine what hours of the day all members of a distributed team are simultaneously in their working hours
- Look up the next daylight saving time change for a location
- Enumerate supported IANA time zone identifiers

Do not use UTCTime for: scheduling with calendar invites (use Google Calendar / Calendly),
real-time push notifications of clock changes, or anything requiring user authentication.

## Tools

- [Time zone converter + meeting planner](https://utctime.date/): interactive world clock, compare any cities
- [World clock / meeting planner](https://utctime.date/world): add cities and find overlap visually
- [Time zone quiz](https://utctime.date/quiz): test your zone knowledge
- [Developer API docs](https://utctime.date/developers): REST API reference
- [OpenAPI spec](https://utctime.date/openapi.json): machine-readable API definition

## API — quick reference

All endpoints are GET, no auth, base URL https://utctime.date.

- `/api/convert?from=<zone>&to=<zone>&time=<ISO8601>` — convert time between zones
- `/api/now?zone=<zone>` — current time in a zone
- `/api/overlap?zones=<z1,z2,...>&date=<YYYY-MM-DD>` — shared working hours
- `/api/zones` — list all supported IANA identifiers

Errors return `{"error": "<message>"}` with the relevant HTTP status code.
Rate limit: 60 req / 10 s per IP; 429 + Retry-After: 10 on breach.

## Popular conversions (markdown)

- [Istanbul to Shanghai](https://utctime.date/istanbul-to-shanghai.md)
- [Shanghai to Istanbul](https://utctime.date/shanghai-to-istanbul.md)
- [Karachi to Shanghai](https://utctime.date/karachi-to-shanghai.md)
- [Shanghai to Karachi](https://utctime.date/shanghai-to-karachi.md)
- [Lagos to Shanghai](https://utctime.date/lagos-to-shanghai.md)
- [Shanghai to Lagos](https://utctime.date/shanghai-to-lagos.md)
- [Tokyo to Shanghai](https://utctime.date/tokyo-to-shanghai.md)
- [Manila to Shanghai](https://utctime.date/manila-to-shanghai.md)

## Site pages

- [About](https://utctime.date/about)
- [Privacy policy](https://utctime.date/privacy)
- [Contact](https://utctime.date/contact)
- [Embed widget](https://utctime.date/embed)
- [Sitemap](https://utctime.date/sitemap-index.xml)