Birth chart
It opens on an example, Ulm on the morning of 14 March 1879, the day Albert Einstein was born there. Every field can be changed, and the address bar always holds a link to the chart on screen.
How this is computed
Positions come from astronomy-engine, which is accurate to within about one arcminute. Birth time uncertainty is a far larger source of error than theephemeris: a single hour changes the Ascendant by roughly 15°, which is enough to change its sign about half the time.
The birth time is interpreted in the timezone of the birthplace. Where a clock change makes a stated wall-clock time ambiguous or non-existent, the tool says so and offers the choice.
Houses default to whole sign. It is the division assumed by the Hellenistic and medieval sources this site quotes, and the only one of the seven offered here that remains defined at every latitude. See Methods for the full account, including the known limits of the other six.