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Birth location and timezone
Why location matters, how historical timezone rules are handled, and what to check when a place looks wrong.
Location determines more than a label
The selected place provides coordinates and helps identify the timezone rules that applied at the birth date. Modern timezone offsets are not always the same as historical offsets, and daylight-saving rules have changed over time.
The platform normalizes the time
You enter the local recorded birth time. The application resolves the selected location and the historical timezone rules needed for the calculation, so you do not have to convert the time to UTC yourself.
If the result looks wrong
Check the selected city, country, birth date, and local time before recalculating. If multiple location results share a name, choose the correct region. Preserve uncertainty instead of silently changing values to match an expected chart.