EtheReal is built with the help of open-source tools and data. We gratefully acknowledge:
Astronomy Engine
Planetary and astronomical calculations. MIT License. © Don Cross. github.com/cosinekitty/astronomy
Luxon
Date and time handling. MIT License. © Moment.js contributors.
Timezone data
Timezone boundaries derived from OpenStreetMap data, © OpenStreetMap contributors, available under the Open Database License (ODbL).
Typography
Fraunces and Spline Sans Mono, via Google Fonts (Open Font License).