1. Understanding Qt 5.15.2 & the “Offline Installer” Concept

1.1 What is Qt 5.15.2?

Pro tip: If disk space is limited, deselect Android, iOS, and obsolete web view modules.

How to Download and Install Qt 5.15.2 Offline Installer

6.2 CMake (modern)

export CMAKE_PREFIX_PATH=~/Qt/5.15.2/gcc_64/lib/cmake
mkdir build && cd build
cmake .. -DCMAKE_PREFIX_PATH=~/Qt/5.15.2/gcc_64
 suncalc.org
reverse calculation
from the sun altitude/azimuth at time
Sun Altitude: 0° - 90°
Sun Azimuth: 0° - 360°
Period calculation:
Accuracy: