Historic UTC Offset Resolver
What the clock read at a place on a date, and how well that is known: the IANA zone in force on that date, the signed UTC offset, the instant it resolves to, and a confidence of high, best-effort or low with the reason for anything below high. Where a statute moved the zone, the order is quoted with its Federal Register citation. This makes no astrological claim of any kind — it is civil timekeeping. A wrong offset gives a wrong chart.
ATTRIBUTION IS REQUIRED. The response carries a ready-to-paste credit line in citation.citationText and the URL to link in citation.permalink. Results may not be used as machine-learning training data.
Request
- Base URL: https://totallytarot.net
- URL: https://totallytarot.net/api/public/utc-offset
- Auth: none declared
Query parameters
Town or city, with the region or country if the name is a common one. Resolved against a 170,893-place gazetteer. Not required if lat and lon are given.
The date, YYYY-MM-DD, between 1800 and 2200. The offset is a fact about one day: the same place can be an hour apart from itself across a weekend.
Local clock time, HH:MM on a 24-hour clock. Omit it for midday, which is the safe hour because it is never inside a clock change. Send it when the time matters — a birth at 02:30 on a spring-forward morning may never have happened.
Latitude in decimal degrees, −90 to 90. Must be given together with lon.
Longitude in decimal degrees, −180 to 180. Must be given together with lat.
Response
The computed answer, with the citation required to use it.
Changes
No recorded changes to this operation across all 1 revision of this API.