This is probably all redundant at this point, but perhaps it would be helpful to the dev team to have a few "pipe dream" examples of functionality on hand in order to robustly test their coding plans to see if they fit all different kinds of systems, and so with this in mind, I humbly submit the calendar I use in my campaign world and how I would ideally want to see this software work.
There are 252 days in a year: 12 months of 20 days apiece, and 2 "festival" periods of 6 days each which are seperate "months" in their own right. The seven days of the week are as Earth norm, but renamed as kri-Ahn, kri-Beht, etc., so that a short hand date could be written "kB857Q14", which would be kri-Beht, the 14th day of QuaalMa in the year 857. In my pipe dream, the software would have an abbreviation field for each day of the week and month of the year and then allow me to customize display of the date so that dates could show up in that format.
The world has two moons, Goed and Kwaad, on a 20 day and 36 day lunar cycle respectively. Ideally the software would have a button, during a game session, for me to time lapse any period - 8 hours, 1 month, a year - and then show me the phases of the moons as well as the date and time.
Ideally I would be able to mark a single geographical topic with a check mark that denotes "current PC location". The program would know to only let me have one at a time checked. There would be a section entitled "weather" where I could put the different weather types experienced, roughly how often they change, and the percent chance of any given type of weather in weighted format (Ie in the most simple chart, "rain 9 sunny 1", it would know that there was a 90% chance of rain every time it rolled). Every time I did a time lapse the system would also let me know whether the weather changed and what the current weather is. (If I didn't put a weather chart on the geographical topic in question, it would ideally have a "Default" one to fall back on).
When printing or displaying the calendar, the headings of any Holiday or Event topics (provided they were revealed) would show up on their corresponding dates, even ones with a rotational date (IE first Tuesday in August, instead of "July 4th"). It would also display dates of the full moons.
So... yeah, I know that's a wicked tall order, and if I can't have everything, eh, such is life. I'm just happy they're looking at doing some of it.
