What does Crux Perpetual mean on CalculationTime?
It belongs to the sky-time silo: celestial position, local observation, printable field reference and transparent astronomical method.
Glossary term
Crux Perpetual
Crux Perpetual is CalculationTime’s Southern Cross sky-time instrument, built around Crux as a visible southern-sky time reference rather than a generic clock face.
History of the term
Southern navigators have long used Crux and the nearby pointers as a practical sky reference. Crux Perpetual turns that old observational habit into a modern web instrument.