Time zones converter

Supply a source stamp such as 2024-06-15T14:30:00, a from_zone of America/New_York, and a to_zone of Europe/London, and the tool yields 2024-06-15T19:30:00 as the converted local time together with a UTC Zulu stamp, a signed offset shift, and a calendar-day note when midnight is crossed. If either identifier is missing from the table the task fails with invalid_input naming the unrecognized zone.

Named IANA zones, fixed offsets, and why this converter does not invent DST

Aliases such as US/Eastern, US/Pacific, GB, Japan, and POSIX Etc/GMT plus-or-minus N resolve to the same canonical names and minutes. That is the product promise behind the time-zones slug: named zones, fixed rules, converted local time, and a hard invalid_input when a name is unrecognized rather than a guessed city or a silent UTC fallback.

How to call the API and how to read every field in the response

POST a JSON body with three required fields. The field datetime is an ISO-8601 wall-clock string: four-digit year, month, day, a T or space separator, hours and minutes, optional seconds, optional fractional seconds that are truncated to whole seconds, and an optional trailing Z or numeric offset that is accepted only so the wall components can be parsed—from_zone remains the authoritative source offset. Aliases for datetime include dt, time, when, timestamp, and datetime_in. The field from_zone is the source IANA identifier, and to_zone is the destination; each accepts canonical Area/Location names, common legacy aliases, UTC, GMT, and Etc/GMT signed POSIX labels, matched case-insensitively with spaces treated as underscores. Aliases for from_zone include from, source_zone, tz_from, timezone_from, and from_tz; aliases for to_zone include to, target_zone, tz_to, timezone_to, and to_tz. On success the response echoes datetime_in as the normalized wall stamp, datetime_in_iso with the source plus-or-minus HH:MM attached, datetime_out and datetime_out_iso for the converted local time, local_time as HH:MM:SS, from_zone and to_zone as canonical names, from_offset_hours and to_offset_hours as rounded hour numbers, matching UTC plus-or-minus labels, offset_diff_hours as to minus from, utc_iso for the same instant in Zulu, year month day hour minute second as integers of the destination civil clock, day_offset as how many midnights were crossed, day_note and message as short English summaries, formula as a one-line identity, and steps as an ordered array of substitution lines you can show next to the answer. Failed validation—missing fields, malformed ISO strings, impossible calendar days such as 2023-02-29, hours outside zero through twenty-three, or an unrecognized time zone name—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item.

Practical tips, limits, related searches, and where this tool fits

Half-hour and quarter-hour zones are first-class: Asia/Kolkata is five and a half hours, Asia/Kathmandu is five hours forty-five minutes, Australia/Adelaide is nine and a half, Pacific/Chatham is twelve hours forty-five minutes. Prefer this capability when you already hold an explicit ISO stamp and two IANA names and you want fixed-offset reproducibility; if you only have numeric UTC plus-or-minus labels, use the offset-to-offset helper instead; if you need summer time, use a DST-aware zone tool. Round-trip checks are easy: convert A to B, then B back to A with swapped zones, and confirm the original wall clock returns after the same absolute instant is reconstructed. Prefer canonical IANA names when you have them (America/New_York, Europe/Berlin, Asia/Tokyo) and let the table fold aliases such as US/Eastern or Japan onto the same offset minutes. Remember the signed shift is always destination offset minus source offset: if the source is America/New_York at UTC-5 and the target is Europe/London at UTC+0, offset_diff_hours is plus five, so fourteen thirty at the source becomes nineteen thirty the same calendar day in London. Crossing midnight sets day_offset to plus one or minus one and the day_note string explains which side of midnight the destination lands on; a Tokyo morning converted toward Los Angeles often lands on the previous calendar day. Pair examples when teaching: same zone leaves the wall clock unchanged; westbound conversion subtracts hours; eastbound adds hours; an unrecognized name such as Not/A_Zone demonstrates the hard invalid_input path. This landing targets people searching for time zones converter, convert datetime between IANA time zones, or named zone local time conversion; it is not a flight-duration calculator, not a DST advisor, not a numeric-only UTC-offset shifter, and not a city-name gap tool that never moves a stamp. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately send a bogus zone.