This is not timely. I should've posted it about a month ago. Even still:
In parts of the world influenced strongly by both Christianity and the Gregorian calendar, many people often have very little idea of what day of the week it is from around Christmas Day to New Year's Day. Between those, they may not even be aware of the date from 27th to 30th December. But because the year lasts fifty-two weeks plus one or two days, we're thrown out of kilter annually and there are fourteen possible calendars.
Putting the two together, there could simply be a year lasting exactly fifty-one weeks, or 357 days, plus an eight- or nine-day period at the end, when nobody thinks about the day or date very much and fewer people are affected by it, which ensures the dates and days of the week remain aligned.-- nineteenthly, Jan 28 2021 By the esteemed Steve DeGroof https://web.archive...idea/28-Day_20MonthMight not have been this one, but I remember a 360 year with a week long party [RayfordSteele, Jan 29 2021] Calendar reform [+].
But this is only a start.
Why not just tweak your planets and moons orbits so that they are integer factors of diurnal rotation ?
Make the moon orbit exactly 30 days; make the planet orbit in 360 days. If moving closer to the primary is undesirable, change it to 390 days.
If you want to stick with a 28 day lunar cycle, then the tweak is even smaller- just 1.2422 days off the planetary orbit.
C'mon, show a bit of initiative...-- 8th of 7, Jan 28 2021 I think the days of the week are the oldest continually functioning Human institution, and I don't like any plans to mess with them, so [-].
Also, people will just continue to observe both the "proper" weekend and the "modernised adjusted" weekend to get twice as many days off, just like the Soviet peasants did when a rational work calendar was imposed on them.-- pocmloc, Jan 28 2021 I do like the general gist, but prefer a lunar-month arrangement of 13 months each of 27 days, with an embolic(?) 14 day holiday during which nothing is allowed to happen. Leap years and adjustments could be worked into this period to keep the lunar months in line with what the moon is visibly up to at the time. I think 14 days ought to be enough to take care of that and to avoid seasonal drift, but part of me thinks if it was that easy, we'd be doing it already.
The other way is to continue have 13 months, of 28 days each and a floating day and a bit - the advantage being that each month would have 4 weeks - but it'd be nice to keep that 14 day period for sorting things out.-- zen_tom, Jan 28 2021 If your birthday occurred during that period the date would be recorded as "between Dec 25th and 1st Jan"-- hippo, Jan 28 2021 //would be recorded as "between Dec 25th and 1st Jan"// I think this goes back, in a way to how the Romans did things prior to Caesar adding two additional months into the mix. They had a 10 month calendar which was mostly lunar, and an extended 61 day winter season that was effectively written off in terms of planning anything. Then August and July got added, annoyingly making September and October, November and December no longer the 7th and 8th, 9th and 10th months as their names would suggest, but the 9th, 10th, 11th and 12th (though another theory is that they fixed that by having the year start in March, preserving the etymological purity of these month-names)-- zen_tom, Jan 28 2021 We did this one a long time ago.-- RayfordSteele, Jan 28 2021 Do you have a precise date for that which everyone can agree on, [Ray] ?-- 8th of 7, Jan 28 2021 An old calendar system did this (or something very similar); a brief dive into Wikipedia didn't refresh my memory. Possibly Roman?-- neutrinos_shadow, Jan 28 2021 Great idea. (since retiring I no longer know what day it is anyway. We could have a 2 day week with nine-hundred months for all I know.)-- blissmiss, Jan 28 2021 [8th of 7] why is the current rotation period sacred? Lengthen the day (and the second to compensate) and the year shrinks without having to move the whole planet. Would mean moving Luna out a bit further than otherwise, but we have plenty of slack before she becomes a planet instead of our moon...-- Selky, Jan 30 2021 Why does the calendar have to correlate to natural cycles? Everyone just use Unix epoch and be done with it-- pocmloc, Jan 30 2021 Because that's simple. obvious and logical. Humans don't seem to do that stuff well.
// [8th of 7] why is the current rotation period sacred? //
It's not, not at all. It's all up for grabs. Angular velocity and orbit can be changed, and moving a bit further from your primary would fix this alleged "warming" thing that some humans seem so worried about.
Rational "year" periods would be either 256 or 512 planetary rotations. The axial tilt could be adjusted, too.
You might have to tweak some of the other planets too, as the gravitational fields do interact, albeit weakly.
It makes about as much sense as a railway gauge of "Four feet, eight and a half inches", or cricket, or representative democracy ...-- 8th of 7, Jan 30 2021 random, halfbakery