MONAD, Stage 1.
Before we got too far along with the programming, there were a number of issues to work out. The original design of the Calendar-Band was a mechanical device, based on two layers of almost 730 individually-sized Day Block tiles. All of this just to account for the Gap. Even after we got rid of the tiles, programming the Gap took up well over half of the programming hours to complete Stage 1.
Figuring out the orientation of the Calendar-Clock within galactic space was not easy. So many coordinate systems to contend with. The primary axis of the ellipse has to be aligned relative to the start of a civil, calendar year. Thankfully, the Astronomical Algorithms of Jean Meeus took care of a lot of these problems.
Getting the Calendar-Band to function dynamically and accurately over the course of time was by far our biggest challenge. Accounting for 24 different time zones, Day Light Savings and Leap year were significant problems.
The very first version of the MONAD App, featuring only a 3D Calendar-Clock and two Modes, Helio and Geo, was uploaded to the App Store September 21, 2018. A solid foundation was laid. We started Stage 2 Programming right away.