Current local time, UTC offset, daylight-saving state and next clock change for any IANA time zone, plus DST transitions and shared working hours across zones.
The World Time API answers the time questions apps and AI agents get wrong. Ask for the current time in one or many zones (by IANA name or an unambiguous city such as "Tokyo") and get the local time, UTC offset, abbreviation, whether daylight saving is in effect, the ISO week, and when the clocks next change. /transitions lists every offset change in a year to the second, with local times on both sides. /overlap finds the UTC slots in a day when working hours overlap in up to 10 zones, across the date line and skipping weekends. /zones lists all IANA zones with their current offset. Old zone names (Asia/Calcutta) resolve to current ones (Asia/Kolkata), and typos get suggestions. Data comes from the IANA time zone database bundled with the runtime; no third-party service is called.
https://apistack.online/api/utilities/world-time/v1utilities