Daylight saving time API guide

How can an API report daylight-saving time?

Call /v1/time/dst as a daylight saving time API or DST API with a timezone, IP address, coordinates, or fixed offset. The response reports whether daylight saving is active and can include the next transition when the selected zone has one.

curl "https://api.timelogicapi.com/v1/time/dst?tz=America/New_York&next=true" \
  -H "Authorization: Bearer $TIMELOGIC_API_KEY"

Select a zone

Use at most one selector family. A fixed offset is a numeric context rather than a rules-based IANA zone, so it always returns dst_active=false.

GET /v1/time/dst?tz=America/New_York&next=true

The same selector choices used by the timezone endpoints are available: tz, ip, lat + lon, and offset. If no selector is provided, the response defaults to UTC. URL-encode a plus sign in an offset as %2B.

Use the transition data safely

Use dst_active with the returned timezone, utc, iso_local, and offset context when explaining a user's local time. If next=true is supplied and a transition exists for the zone, the response includes the next transition information. Do not infer DST from a numeric offset alone, because the same offset can occur in zones with different rules.

Fixed offsets do not have DST rules and return dst_active=false. Use the DST endpoint reference for parameters and signed responses when the result must be verifiable.