Guides

Long-form explainers that go with our calculators. Each one is built on numbers we computed with our own engine or on sources we name, and links to the tool that lets you check it against your own chart.

• How exact does your birth time need to be?

  Published October 21, 2026 · We moved 5,000 sample births by 5 to 60 minutes and counted what changed: the rising sign, the houses, the Moon and the Sun. Here is how much a clock error matters.