What is the FWK

The "Fixed Week Calendar" (DE: Fixierter Wochenkalender) is a calendar similar to the International Fixed Calendar except it makes sure the week starts on a Monday as per the internationally agreed on time keeping standard ISO 8601. In this calendar, each year has the exact same layout. There's 13 months with exactly 4 weeks à 7 days for a total of 28 days each. This results in a year being 364 days long.

To fix the discrepancy with a real year, every year ends with a special day called "year day" that is not part of a week. The change from the last week of a year to the first week of the next year looks as follows:
..., Saturday, Sunday, Year day, Monday, Tuesday, ...

Leap years also exist, and they follow the rules of the gregorian calendar. This day is inserted in a similar fashion as the Year day at the end of June. This day also does not belong to a week.

The Gregorian calendar contains a leap year in every year where at least one of these two rules are met:
- The year is divisible by 400
- The year is divisible by 4 but not 100

The extra month is called "Sol" (Named after the sun) and sits between June and July.

You can download the FWK calendar script here. Or if you prefer typescript, here.

FWK has no impact on how we keep time. If you want to change that too, I can offer you decimal time.