If you are interested in the relation of Nature and Culture, think a bit about the calendar. A year is anchored to the earth's rotation around the sun which takes just over 365 sunrises to complete. Between half of those sunrises, the periods of daylight get longer and between the other half, they get shorter.
On this basis, we have constructed months, weeks, and 24 hour days.
There is clearly something dodgy about months. They aren't all the same length (poor old February) which has something to do with the fact that 365 does not divide exactly by any number higher than five (Correct?). A month bears a rough relation to the length of the female menstrual cycle but I don't think it has any other anchor in the non-social world.
You could have nine months each of 40 days and then five and a bit left over, which could be fun. Nine months would be roughly related to the length of a human pregnancy. Or you could dispense with months and have 73 five days weeks - you would just have to remember which week you were in.
Our actual seven day weeks have been around a long time. It was a good idea for the writers of the Old Testament to offer a day off in seven in return for accepting their favoured structure. But one day off in five would have been a better deal.
Hours, minutes and seconds ...
We live in societies which have become 24/7 - societies in which day and night no longer matter and in which everything is always open. This is the achievement of electric light, central heating, the Internet and Tesco.
24/7 shows how bizarre is the thinking of British governments. The last one even reached an agreement with General Practitioners - doctors - which allowed them to shut up shop on Saturdays, Sundays and Bank Holidays and hand responsibility to "Out of Hours Services". It doesn't work. If you get ill at weekends, you are more likely to die because "Out of Hours" is unlikely to understand what might be wrong with you. Some of the doctors who cover at weekends fly in from Europe (it's cheap)to earn a bit of extra cash. Sometimes they kill people because they don't speak English or because they specialise in cosmetic surgery (and that's just one recent case).
It's a good job your local kebab shop doesn't have a hot line to the British government. With a staff of four or five, a kebab shop normally opens 14/7 and 364/365. The staff work on a rota (a what? ...). Since most GP surgeries have a similar sized - or larger - staff, there seems no reason why they should not do the same. After all, they are paid more. Or would you prefer it that your local kebab should operate the same hours as your doctors' surgery?
Electricity, central heating and the Internet allow us to think more imaginatively about how we structure and use the time available to us. Tesco has understood this. British Governments never will.