24 x 61 Calendar

In this thought experiment,
This calendar grouping has a period of 4 years, an Olympiad, during which there are 24 quad months of 61 days, omitting 3 days from either:

• the 4^th, 12^th, and 20^th dual month – to evenly space them.
• the 8^th, 12^th, and 24^th dual month – to evenly space them.
• the 1^st, 7^th and 13^th dual month, if Olympiad starts on 1st January
  – to keep alignment with the Roman calendars’ end of year.

There are 6 dual months per year, and 4 years per Olympiad.