Skipped/Dropped Years Feature

[dylanater11]

Problem
I was working on trying to translate the Coligny Calendar into Fantasy Calendar. This calendar is lunar-based. The issue lies in that this calendar achieves it's accuracy without drifting, by having 4 cycles of 5 years... However, the first year in the first cycle is actually "dropped" as in, there are no days in it. What this means, is that all of the intercalary months can be on a consistent "every 5 years" cycle without messing up the 19 year cycle.

For a visual example, the table located in the "The solar year" header on the Coligny Calender wiki page best displays this. You can see the column labeled "y1" has 0 listed for all of the day counts.

Solution
A feature to allow users to add "drop years." So that you could set the calendar to "skip" a year, every Nth of years. This skipped year would increment all of the things on an interval (such as intercalary days, or months) but would NOT step an actual day forward, which would mess up the lunar cycle.

Alternatives
I haven't really thought through the implementation completely, there might be underlying reasons why coding something like this would be pain. So perhaps instead of the specific feature I suggested, there could be a more eloquent solution related to a "lunar calendar" option.

Other Notes

• I saw that lunar calendars were mentioned in this issue. I almost commented this to keep it grouped with that post, but figured this would be best as a separate feature request.
• This is a pretty niche feature, so I understand if it's not a priority or even considered.
• If there is actually a way in the current version to achieve what I want I would love to hear it! But from what I can tell, this type of "dropped year" thing can't be done.
• P.S. Such a cool app, thanks for making it!

[dylanater11]

Just wanted to add a note, this feature could obviously be extended to allow for "Drop Months" and "Drop Days" as well. While the feature is definitely niche for people working with particularly wonky calendars this could be one of the final pieces that allows for corrections.

I'm also wondering if a "Negative Leap Day" would achieve this? If you could have every month in a year "skip" at the end of 19 years, or effectively leap a single time, then cycles and such would move forward as if a year as passed, but the lunar and solar cycle would not be effected! I could totally be wrong about this, but "Negative Leap Days" does sound like it would work. Moving on with that idea, people could use it to correct for very minute issues in their solar/lunar synchronicity. For instance, even the Coligny calendar would need to drop a month every 6,536 years in order to not allow solar slippage to take over. It also needs to drop a day every 61 years. Negative Leap Days/Months would allow for this.

Edit: You could have a month skip every 6536 years if you were able to type in "!6536,1" into the interval slot for months. But it seams you cannot! Request 2: Expansion of the leap month feature to allow for the same inputs as leap days.

Sorry for the mess of writing! Just hope this spurs ideas if anything! :)