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One frequent target of calendar reform in the West has been the preservation of the seven-day cycle of the week. A common feature of 20th-century calendar reform has been the treatment of one or more days of a year as blank days, which belong to no month and are not designated as a day of any week. This scheme destroys the continuity of the seven-day cycle, which has been carefully preserved for some two millennia. Major objections to reform calendars were raised by religious groups for whom the preservation of the seven-day cycle was important, and the reformers reserved some of their best vitriol and dismissive posturing for those groups. |
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Although these feuds are of historical interest, the question remains. How important is the preservation of the weekly cycle? |
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There is no single right answer, of course. I believe that the preservation of this cycle is important. The reasoning is not religious, but rather based on considerations of information. |
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As you have seen, it is possible to calculate the day of the week (DOW) quickly and easily by simply dividing the Julian Day number by seven and using the remainder as an index. This simple rule works for any Western calendar date. |
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Now, this calculation or result in itself is not important. But it does remind one of the power of continuous cycles. A cycle, when it is continuous, allows us to determine useful details at a distance. To break a continuous cycle means throwing away potentially useful information. Information should never be deliberately thrown away. |
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Look at the same structural situation clothed in different details. Jack Wolfe, in a very clever paper (Nature, pp. 420423), described a paleontological site near Teapot Dome in Wyoming, which involves the Cretaceous/Tertiary (K/T) boundary. The site was a lily pond, in which the aquatic plants were suddenly killed and their roots pulled from the pond bottom. By performing a detailed paleobotanical analysis of the site, Wolfe was able to establish that an "impact winter" had killed the plants, which had subsequently been pulled from the bottom by ice. |
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By looking at the stages of maturity of the fossil plants, Wolfe was able to establish that certain species had reached maturity, while others had not, and could thus determine from comparison with maturity dates in extant relatives that the bolide impact occurred in early June. |
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This is a remarkable conclusion. The K/T boundary cannot be dated with an error much better than several million years, but Wolfe was able to suggest a date within a year with an error of about two weeks. When you see a date like, "One million B.C., a Wednesday," you are meant to laugh, because the date claims an accuracy in smaller time units that is absent in the larger units. Yet this is exactly what is done in the case of Wolfe's paper. |
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The key to this accuracy, of course, is the annual cycle. You do not know which year is involved, but you know something of the fine structure of that year, because a continuous cycle of seasonal events occurs. The continuous cycle is a kind of "time wave", which allows us to investigate certain events at great temporal distance. |
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