Locking the calendar to the seasons is really valuable if you work on a farm or do other seasonal work. However, anyone who doesn't need to track the seasons may prefer the 6/5/30/12 simplified model.
There would be some adjustment, like "winter" holidays occurring in the summer. Although anyone who lives in different climates or moves between the northern and southern hemispheres will already experience something similar.
A good question may be how often would you need to calculate or look up something that the other calendar would make obvious. The better calendar (for you) is the one that reduces those occurrences.
How is seasonal data important for modern farming operations? Farms want even more precise weather data which they can augment to their own calendars. Most people care far more about weekly weather variations and will not experience difficulty in determining when summer is coming.
Also, given the variation that people experience across geography, my per-month weather is quite different from yours. A global synchrony is not fit for farming operations. How much of the world even experiences a beautiful alignment of the seasons to their calendar?
Further, the kinds of adjustments people are proposing is not going to knock anyone off their ability to schedule around entire seasons. People are proposing tiny roundoffs to eliminate calendar idiosyncrasies (excluding the offhand 360 suggestion, which while "small" is going to lead to more idiosyncrasy).
I think you're understating these adjustments. Christmas happening in the summer? School "summer break" happening during winter? These are massive changes
I don't think either of those adjustment would occur.
I know my highschool didn't have AC, so the summer break needed to happen in the summer. I expect the school year would continue to follow the seasons (unless, maybe, we had really cheap AC?). It would be strange to have the school year start in different months, but you'd get used to it. I know I already need to look up when the school year starts; it shifts a little already due to holidays and the days of the week.
Personally, I grew up with cold winters and liked Christmas as a snowy winter holiday. But when I moved and had warmer winters and less defined seasons, Christmas came and it didn't really feel like winter. A summer Christmas wouldn't be noticeably different here.
I like the idea of a major winter holiday for anyone struggling through a cold winter. For many people, that's currently Christmas, and I suspect the US and similar climates would benefit from keeping it seasonal.
But what's the actual value proposition of having a simple regular calendar if all of the important dates that people care about move around on it all the time? Sure, maybe you always know what date it is, but now you don't know what's happening on that date. The end result is the same level of complexity, it's just that now the date numbers are useless.
> all of the important dates that people care about move around
What dates do you care about?
I know my calendar is full of one-off events, and the recurring events follow the calendar, not the seasons. For these, a 6 day week/30 day month would be easier. That weekly Monday meeting? Always on the 1st, 7th, 13th, 19th, or 25th. The next federal holiday? We can make those always fall on a Monday if we wanted.
I can see that the start/end of the school year is important, but that already moves around enough that you need to look it up. If you are looking for best dates to take a beach vacation, yes, you'd need to look at the seasons.
There would be some adjustment, like "winter" holidays occurring in the summer. Although anyone who lives in different climates or moves between the northern and southern hemispheres will already experience something similar.
A good question may be how often would you need to calculate or look up something that the other calendar would make obvious. The better calendar (for you) is the one that reduces those occurrences.