Birth times and time zones

Most wrong charts come from a wrong time zone, not a wrong calculation. A minute of error moves the ascendant by about a quarter of a degree, and an hour can change it completely.

Send the local time and a zoneCopy Anchor Link

Send what is on the birth certificate, with no offset, and an IANA zone name:

{ "datetime": "1990-10-18T14:30:00", "timezone": "Asia/Kolkata", "latitude": 28.6139, "longitude": 77.209 }

We work out the offset that zone had on that date, including old rules and summer time. Do not work out the offset yourself and do not convert to UTC first. Many apps get this wrong by using today's offset for a date decades ago.

If you only have a fixed offset, send "utc_offset": "+05:30" in place of timezone.

Finding the placeCopy Anchor Link

geo-search searches about 780,000 places, and each result includes its zone and the offset on the date you give:

curl https://api.96astroapi.com/v1/utilities/geo-search \
  -H "Authorization: Bearer $ASTRO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "name": "Delhi", "date": "1990-10-18", "time": "14:30" }'

If you already have coordinates, timezone-at gives the zone for them.

Clocks that went back or forwardCopy Anchor Link

Some local times happen twice, when clocks go back, and some never happen, when they go forward. resolve-instant tells you which, so that you can ask the user:

{ "timezone": "Europe/London", "date": "1990-10-28", "time": "01:30" }

If you send an ambiguous or impossible time to a chart endpoint, the answer tells you rather than guessing silently. See Requests and responses.

When there is no birth timeCopy Anchor Link

Say so in your product, and do not fill in 12:00 without telling anyone. See Handle an unknown birth time.