Credits

Astrely stands on open data and open-source software. Here is what it uses, who made it, and under which licence.

• Place data

  Place data © GeoNames (geonames.org), CC BY 4.0. Built from the GeoNames dump of 8 November 2026.

  The index is the cities5000 extract with names folded for searching and time zones corrected from boundary data; it has been changed from the original.

• Time zone boundaries

  Time zone boundary data from timezone-boundary-builder, built from data © OpenStreetMap contributors and available under the Open Database Licence (ODbL), used through the geo-tz library.

• Astronomy

  Planetary positions are calculated on top of astronomy-engine (astronomy-engine@2.1.19), an open-source library by Don Cross under the MIT licence.

• Reference data

  NASA/JPL Horizons is the reference the position tests are checked against. Swiss Ephemeris 2.10.04 from Astrodienst is the reference for the lunar nodes and the house cusps in the same tests.

• Fonts

  The zodiac and planet glyphs are set in Noto Sans Symbols and Noto Sans Symbols 2. Text is set in Inter and Josefin Sans. All four are licensed under the SIL Open Font License 1.1.