This page identifies the external data services and reference categories used by the theme so visitors can distinguish calculated astronomy from live third-party data.
Solar Calculations
The theme performs its solar geometry calculations locally in the visitor’s browser using standard astronomical equations for solar position, hour angle, twilight thresholds and apparent horizon events. The implementation should be checked against established astronomical references before publication of any specific accuracy claim.
Location Search
Place search and reverse geocoding use OpenStreetMap data through Nominatim. Requests are made only after a visitor searches for a place or asks the site to resolve coordinates.
Weather and Time-Zone Metadata
Current weather and time-zone metadata use Open-Meteo. Open-Meteo combines and normalizes forecast-model data from national and international meteorological services. The weather card links to its source and the site owner is responsible for using the appropriate Open-Meteo licence or commercial plan.
Corrections and Reproducibility
When reporting a discrepancy, include the coordinates, date, time zone, event being compared and the comparison source. That makes it possible to distinguish a coordinate or definition difference from a calculation error.