Birthplace Atlas & Time Zone
Find a town, check its coordinates and IANA time zone, and resolve the UTC offset that applied at a recorded local date and time.
1. Find a town
Enter at least two letters. Add a comma and region or country code to narrow results.
2. Check the local time
How the birthplace lookup works
Start with the town printed on a birth record. Search by name, then inspect the region and country before choosing a result. For a common name such as Springfield, add a comma and the state or country to narrow the list. Each result gives a coordinate pair and an IANA time-zone identifier. The place list comes from GeoNames cities5000 and includes towns above roughly 5,000 residents plus administrative seats. A small birthplace may be absent; choose the nearest appropriate reference only after checking the original record and local jurisdiction.
Enter the recorded local date and clock time. The selected zone's historical rules determine the UTC offset that applied at that local moment. It tests possible instants and returns the matching UTC time and offset. The date range is 1800–2100, using the Gregorian calendar.
Daylight saving and repeated clock times
During a spring clock change, an interval of local time can be skipped. If the entered time did not occur, the tool says so instead of inventing a UTC instant. During an autumn change, the same clock reading can occur twice with different UTC offsets. Both occurrences are shown, and you must select the one supported by the record. This choice can change an Ascendant or house calculation. For example, 01:30 in New York on 3 November 2024 occurred once at UTC−04:00 and again at UTC−05:00.
A current time-zone offset is not a reliable substitute for a historical one. City boundaries, political changes, and daylight-saving rules have changed. The browser's historical database may also be less certain before 1970. When an older or disputed record matters, compare the result with a historical civil-time source. Historic offsets can contain seconds; keep the full value when entering a chart calculator.
Coverage and accuracy
Town names, administrative regions, coordinates, and zone IDs come from a locally stored extract of the GeoNames cities5000 gazetteer (69,735 records), licensed under CC BY 4.0. Historical offset rules use IANA time-zone data, which may differ between devices. The city selection suggests a coordinate and zone; it does not verify anyone's personal birth location.