This page tests some of the functions and algorithms the site relies on. In most cases, you should see only tiny differences between the reference values and the values calculated by observability.date. The ratio column is highlighted in green for quantities that are accurate to better than one part in a million, yellow for better than one part in a thousand and orange for worse than one part in a thousand. For the purposes of testing, the results of
getLunarSigmas() shown here use all the coefficients listed in Meeus, while in the actual observability calculations, smaller periodic terms are dropped. The accuracy in practice is about 1 per cent.
observability.date version number:
Results from observability.date are compared to results from PHP
date_sun_info(). These tests are not properly defined yet.