bem

Thanks for this post.
I suggest we use the matrix model I showed (nothing to do with the movie, but with the artificial matrix of number obsessions and the natural source of our counting systems, the 10 fingers)
Now, what natural cycles in nature, which we can define with numbers and days, are there ?
We got many.
We got the "sun cycles", basically, the day and the year.
This affects nature a lot, we get light and darkness periods, we get seasons, we also get basic counting.
We got the "moon cycles", (day/night semi-cycle of appearing/disappearing, but still in a different manner every day/night, relative to the steady SUN) and a more basic lunar-moon-month cycle, with effects of new-moon/full-moon, and tides, and a correlation to many other natural cycles in nature, such as the human female menstrual cycle.
Other cycles, are also according to the planets, and the constellations.
There are about 7 classical planets, each with some uniqueness attributed to it in each day on the week, showing some possible correlation to nature (like each one of them is closest to the sun, relatively, for Earth's viewpoint, and also the Sun is seen as moving through different "background of stars" as seen from earth, which is divided to 12 or 13 constellations, usually, in according to the cycle of the moon, originally.
(Hebrew new moon is always a new month, and many celebrations are in the middle of the month, on the full moon, The Hebrew calender goes by the moon and the sun, thus using a 12 months years, with a 13 moon year every few of years, on a fixed cycle, causing the same holidays to appear always in the same seasons and in the same moon-phase)
Some basic astrological FACTs we can show so far:
It's possible to assume that people that are born in the summer are somewhat statistically different from those that are born in the winter-time.
It's possible to assume that the summer is hotter and the winter is cold and rainy, in the northern hemisphere, almost always, and this seems to be the way it goes forever, even with possible "pole shifting" (think about it if you need to).

Now, what happens with calenders and other artificial (human-made) number-usings ?
You use a counting system based on 10 fingers.
The intelligence you referred to in the above-mentioned-animal, will be activated not by "counting 28's", but by this possible "analogy to counting in the animal kingdom":
- I count much light in night, so I go to hunt
- I count much animals I can eat, so I know it's good to do it. (possibility, the first is enough of course for most predators, and other animals that are attracted to light, with bugs being a common example, which could be widely and wisely used by the predators)
- I count less light in night, and then more light at night and then less and then more, so I know the the more I reach the maximum, I should be in the place where I saw most animals, and I should come closer to it, if I see the light-night is getting stronger each-"day", and in the maximum-light-night I'm going to be there for sure. Mmm, maybe I should convince others that my counting is good, I might yell and houl in full moon to convince my fellow predators that it's the numerological-feeding-time.
- If I had intelligence I would build a calender to make us all go together to hunt on full moon without having to shout and scream about it, but I have 16 fingers on 4 limbs, so I will count this cycle of feeding-time differently from animals who don't hunt, don't believe the full moon affect nature as I do, don't feed at night but do other things at night that they can see better under the moon, stand on 2 legs, use 10 fingers, 5 of them usually more than others, and 1 finger in each hand is opposite to the others, and they don't seem to have a tail on themselves to count with.

Interesting to add:
The cycle of the week/weekend is believed to be of a religious biblical source and not of normal nature. It is nice to see that the name for Saturday, both in English and in Hebrew, shows a linguistic connection to the planet of Saturn (Shabtai in Hebrew, Saturday is Shabat, or Sabbath in English translation of the concept)
(The classical list of planets is obviously "not accurate enough", since they count the sun and the moon (reflected in the western calender as Sunday and Monday, and only other 5 planets, but this might be also corresponding to some natural-effect-of-the-universe as seen from earth, and also corresponds to the 28-days moon cycle, dividing it to 4 basic halves (one half, and then another half of each half, I don't divide the moon cycles to thirds, but to halves, and I get a pretty good correspondence to new-moon, half-moon, full-moon, half-moon, which is also in according with cycles of sex, since the cycles of sex are affected by moon-periods, and by weekends, in some way that can naturally reflect our "forgotten" full-moon-hunting-obsessions,

Doesn't have to be "nurture" per se.
Calenders are, as you said, numbers that represent something, or a numero-system of time of a year. And when you represent the number of the calender based on a counting system of 10-fingers, that can cause "possible fears, not directly connected to nurture".

When are we afraid of dates ?
1.
When money is involved, usually without any connection to Nature. we get our salaries and pay our taxes on a money-calender, and it can cause some fears about it.
2.
When the year is getting close to its end.
Many people feel that "wow, time goes by so fast, I don't notice this, hey, I'm getting older, could it be 2008 already ?"
Nothing really connected to nature, but to the representations of numbers (some are more depressed on the winter anyway, of course, but some calenders end in the summer and causes a "ending effect" without the possible winter-depression.
Different "human made calender" also can cause us fears:
The school year calender is quite artificial and fixed, and causes many possible fears, like when the vacation is Ending.
Many things in society go by an artificial calender: TV broadcasts on specific seasons and precise hours, "work-calender" "tax-year-calender" "birthday-calender" "school calender" "dead-lines-calender" "reviews calender", and so forth.
Also, when the mayan calender is over, some fears can be created, and as shown above, fears about the end of time, are (in 3 main cultures) with complete symbolic analogy to the fear/faiths of the end of the year-calender (of the same culture).
3.
When dates remind us of things we fear, or if specific dates "succeed" to frighten us. or if specific dates cause people to do "bad stuff" (more, statistically), as if they are in a full-moon-hunt.
All this Reminding, and possible outbreaks, are all using the artificial way we represent dates, an artificial representations of time, always using some 10-fingers-counting-side-effects, even if it is built as much as possible to conform to the natural cycles of the year / moon / week / day / rest-of-nature, and even when counting hours and minutes and seconds, with artificial models built on previous artificial models:
24 hours a day, on two 12 cycles of numbers, as the day is the "sun cycle", and the sun-cycle is connected to 12-moons-possibility, and is more easily handled, humanly-fingerly-digitally-mathematically, than a 13-hours cycles
60 minutes and 60 seconds show both the X0 pattern of 10-digits-systems, and is also connected to 12, as it is 12 * 5 (we have 5 fingers), and contains the 6 digits, which is half of 12 (I already now 5 is half of 10 with my fingers, and I think half is more important than third, because I divide my 10 fingers to two hands, when counting, not to 3 hands, and I also think that multiplying by 5 is more easily understood, when you have 5 fingers in each hand, and not 3, or 4, or some kind of difference between the number of toes and fingers)

Yes, I appreciate the Mayan-2012 people who aspire to using a calender that is more according to nature.
But you don't need to replace one artificial calender with another one. (you can say it's not artificial and designed by a divine entity, but you can't understand and use it without using your basic models of counting with 10 fingers, or without models of counting using the basic 10-counting model).
If freedom from time is what you want, after 2012 my theory shows time will be less dangerous and less charming, as far as human-destruction and charm go.
If freedom from your calender is what you want, that consider that a freedom from A calender is what you want.
If a natural cycle calender is what you want, just look at nature directly,
If a natural-based calender is what you want, all calender are naturally based somehow, and the basic naturals things about it are:
Earth, Sun, Moon, Day, Month, Year, Week, and a 10-fingers-human.
If you think the western calender should be replaced because it bad, and evil, and enforcing unnatural structures, please note that after 2012, it will be less "evil", less "charming", and thus, "less composing unnatural numbers".

(for all those who forgot or don't know: "Digit" originally means "Finger", check it out)