{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"time-zone-converter"},"result":{"entity_type":"calculator","id":"time-zone-converter","calculator_id":"time-zone-converter","canonical_url":"https://tttkmbb.com/time/time-zone-converter","name":"Time Zone Converter","title":"Time Zone Converter – Convert a Date and Time Between IANA Time Zones with Daylight Saving","category":"time","category_name":"Time & Geography","tool_name":"convert_time_zone","featured_mcp_tool":true,"description":"Converts a wall-clock date and time from one IANA time zone to another using the tz database rules built into ICU, so the daylight-saving offsets in force on that date are applied automatically. Reports both UTC offsets, the UTC instant, the weekday and the day difference.","use_when":"You need to know what time an event scheduled in one city corresponds to in another city or in UTC on a specific date.","do_not_use_when":"You need the same instant in many zones at once (use world-clock), an epoch value (use unix-timestamp), or the elapsed time between two clock times (use time-duration).","inputs":[{"name":"date","label":"Date","type":"date","required":false,"default":"today","description":"Calendar date of the source time in from_zone (YYYY-MM-DD); defaults to the current UTC date.","example":"2026-09-23"},{"name":"time","label":"Time","type":"string","required":true,"description":"Wall-clock time in from_zone, 24-hour HH:MM (seconds optional).","example":"09:00"},{"name":"from_zone","label":"From time zone","type":"string","required":true,"description":"IANA time zone of the source time, e.g. Australia/Adelaide, Europe/Berlin or UTC.","example":"Australia/Adelaide"},{"name":"to_zone","label":"To time zone","type":"string","required":true,"description":"IANA time zone to convert to, e.g. America/New_York or Asia/Tokyo.","example":"America/New_York"}],"outputs":[{"name":"converted_date","label":"Date in target zone","type":"date","decimals":4,"description":"Calendar date in to_zone."},{"name":"converted_time","label":"Time in target zone","type":"string","decimals":4,"description":"Wall-clock time in to_zone (HH:MM)."},{"name":"converted_datetime","label":"Target date-time","type":"string","decimals":4,"description":"ISO 8601 date-time in to_zone including its UTC offset."},{"name":"converted_weekday","label":"Weekday in target zone","type":"string","decimals":4,"description":"Day of the week of converted_date."},{"name":"from_utc_offset","label":"Source UTC offset","type":"string","decimals":4,"description":"UTC offset of from_zone at that instant (±HH:MM)."},{"name":"to_utc_offset","label":"Target UTC offset","type":"string","decimals":4,"description":"UTC offset of to_zone at that instant (±HH:MM)."},{"name":"from_abbreviation","label":"Source zone abbreviation","type":"string","decimals":4,"description":"Short zone name from ICU (e.g. EDT); 'GMT+9:30' style when the zone has no common English abbreviation."},{"name":"to_abbreviation","label":"Target zone abbreviation","type":"string","decimals":4,"description":"Short zone name of to_zone at that instant."},{"name":"utc_datetime","label":"UTC","type":"string","decimals":4,"description":"The same instant in UTC (ISO 8601)."},{"name":"day_difference","label":"Day difference","type":"integer","unit":"days","decimals":4,"description":"converted_date minus date: −1, 0 or +1."},{"name":"time_difference_hours","label":"Time difference","type":"number","unit":"h","decimals":2,"description":"to_zone offset minus from_zone offset at that instant; positive when to_zone is ahead."}],"input_schema":{"type":"object","properties":{"date":{"description":"Calendar date of the source time in from_zone (YYYY-MM-DD); defaults to the current UTC date.","type":"string","format":"date","default":"today","examples":["2026-09-23"]},"time":{"description":"Wall-clock time in from_zone, 24-hour HH:MM (seconds optional).","type":"string","examples":["09:00"]},"from_zone":{"description":"IANA time zone of the source time, e.g. Australia/Adelaide, Europe/Berlin or UTC.","type":"string","examples":["Australia/Adelaide"]},"to_zone":{"description":"IANA time zone to convert to, e.g. America/New_York or Asia/Tokyo.","type":"string","examples":["America/New_York"]}},"additionalProperties":false,"required":["time","from_zone","to_zone"]},"output_schema":{"type":"object","properties":{"converted_date":{"description":"Calendar date in to_zone.","type":"string","format":"date"},"converted_time":{"description":"Wall-clock time in to_zone (HH:MM).","type":"string"},"converted_datetime":{"description":"ISO 8601 date-time in to_zone including its UTC offset.","type":"string"},"converted_weekday":{"description":"Day of the week of converted_date.","type":"string"},"from_utc_offset":{"description":"UTC offset of from_zone at that instant (±HH:MM).","type":"string"},"to_utc_offset":{"description":"UTC offset of to_zone at that instant (±HH:MM).","type":"string"},"from_abbreviation":{"description":"Short zone name from ICU (e.g. EDT); 'GMT+9:30' style when the zone has no common English abbreviation.","type":"string"},"to_abbreviation":{"description":"Short zone name of to_zone at that instant.","type":"string"},"utc_datetime":{"description":"The same instant in UTC (ISO 8601).","type":"string"},"day_difference":{"description":"converted_date minus date: −1, 0 or +1. Unit: days.","type":"integer","x-unit":"days"},"time_difference_hours":{"description":"to_zone offset minus from_zone offset at that instant; positive when to_zone is ahead. Unit: h.","type":"number","x-unit":"h"}}},"formula":"utc = date + time − offset_from(date, time); converted = utc + offset_to(utc); time_difference_hours = (offset_to − offset_from) / 60","method":"Offsets come from the IANA tz database as shipped with ICU (Intl.DateTimeFormat), including historical and future daylight-saving rules known at build time. A source time that does not exist because clocks jumped forward is moved forward by the gap; a time that occurs twice during a fall-back hour takes its first occurrence.","sources":[{"name":"IANA Time Zone Database (tz)","url":"https://www.iana.org/time-zones","type":"standard","retrieved_at":"2026-09-24"},{"name":"List of tz database time zones (Wikipedia)","url":"https://en.wikipedia.org/wiki/List_of_tz_database_time_zones","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"daily","max_age_seconds":86400,"note":"Depends on the current date unless the date is supplied."},"examples":[{"name":"09:00 Adelaide → New York on 2026-09-23","inputs":{"date":"2026-09-23","time":"09:00","from_zone":"Australia/Adelaide","to_zone":"America/New_York"},"expected":{"converted_date":"2026-09-22","converted_time":"19:30","converted_weekday":"Tuesday","from_utc_offset":"+09:30","to_utc_offset":"-04:00","utc_datetime":"2026-09-22T23:30:00Z","day_difference":-1,"time_difference_hours":-13.5},"url":"https://tttkmbb.com/api/v1/calculate/time-zone-converter?date=2026-09-23&time=09%3A00&from_zone=Australia%2FAdelaide&to_zone=America%2FNew_York"},{"name":"12:00 Los Angeles → Kolkata on 2026-07-04","inputs":{"date":"2026-07-04","time":"12:00","from_zone":"America/Los_Angeles","to_zone":"Asia/Kolkata"},"expected":{"converted_date":"2026-07-05","converted_time":"00:30","from_utc_offset":"-07:00","to_utc_offset":"+05:30","utc_datetime":"2026-07-04T19:00:00Z","day_difference":1,"time_difference_hours":12.5},"url":"https://tttkmbb.com/api/v1/calculate/time-zone-converter?date=2026-07-04&time=12%3A00&from_zone=America%2FLos_Angeles&to_zone=Asia%2FKolkata"}],"faq":[{"q":"Which zone names are accepted?","a":"IANA names such as Europe/Paris, America/Chicago, Asia/Singapore or Australia/Perth, plus UTC and fixed zones like Etc/GMT+5 (note the reversed sign). Abbreviations such as 'CST' are ambiguous and mostly not accepted."},{"q":"How is daylight saving handled?","a":"Automatically: the offset of each zone on the given date is looked up in the tz database, so a 9:00 Adelaide meeting in September lands at 19:30 the previous evening in New York, but at 18:30 once Adelaide starts daylight saving in October."}],"tags":["time zone converter","convert time zones","what time is it in","utc offset","daylight saving time","meeting time"],"related":[{"calculator_id":"world-clock","reason":"Show one instant in a whole list of cities."},{"calculator_id":"unix-timestamp","reason":"Turn the same instant into Unix epoch seconds."},{"calculator_id":"time-duration","reason":"Hours and minutes between two clock times."}],"links":{"html":"https://tttkmbb.com/time/time-zone-converter","markdown":"https://tttkmbb.com/time/time-zone-converter.md","json":"https://tttkmbb.com/time/time-zone-converter.json","api":"https://tttkmbb.com/api/v1/calculate/time-zone-converter","schema":"https://tttkmbb.com/api/v1/calculators/time-zone-converter","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:47:52Z"}