The early Romans observed a regular eighth day market and semi-holiday. This might be connected with the African institution, but as yet cannot be historically linked with it.
In the less advanced states of Indo-China and many of the East Indian islands, even as far as New Guinea, five-day markets are the rule. This entire tract has many internal culture connections, so that within its limits diffusion has evidently again been active.
In ancient America, markets were customary every fifth day in Mexico, third day in Colombia, tenth day in Peru. These were also days of assembly and cessation from labor.
The American instances establish beyond cavil that some of these market weeks are truly independent evolutions. Moreover, they nearly all occur among peoples of about the same degree of advancement, at any rate on the economic side of their cultures. But it is only the idea, the outline of the institution, that is similar; its concrete cultural execution, as expressed in the length of the period, differs in Asia and Africa, and in the three American regions. That the Mexican and Southeast Asiatic weeks were both of five days, means nothing but the sort of coincidence to be expected when the choice of duration is limited to a small range, such as between three and ten days.
129. Leap Days as Parallels
Finally, there is a correspondence between the Egyptians and Mexicans in recognizing the solar year as composed of 360 + 5 days. The Egyptians counted the 360 in twelve months of thirty days, the Mayas and Aztecs in eighteen groups of twenty days; both agreed in regarding the five leap days as supplementary and unlucky. This last fact looks like a close correspondence, but analysis dissolves much of the likeness. The solar year consists of 365 days and a fraction. There is nothing cultural about that phenomenon except its recognition. Careful observation continued for a long enough period inevitably yields the result. But 365 is indivisible except by 5 and 73; 360 is much “rounder,” that is, divisible by many numbers, and these “simple” like 6, 10, 12, 18, 20, 30, and therefore easier to operate with. This again is a mathematical, not a cultural fact. The five supplementary days thus scarcely represent any distinctive achievement. As to their being considered unlucky and evil, that is unquestionably a true cultural parallel.
At the same time, this parallel cannot be enacted into any generally valid law. The ancient Hindu calendar, being directly lunar, had about twelve days left over each solar year end at the winter solstice. These twelve days were looked upon as prophetic and portentous, but not as specifically evil. The Persian and Armenian calendars, seemingly derived from the Egyptian, had the same five supplementary days. But in the former the first of its five is reckoned as lucky, only the third as unlucky; and in the latter, none of the five has any special value or observance. Our own twenty-ninth of February is supplementary and we hold a half serious belief or superstition in regard to it and its year, but this has nothing to do with luck.
In short, the human mind does tend to attach an unusual value to any day in the calendar that is in any way outstanding. This observation is a psychological one, and could be predicted from what is known of the principle of association in individual psychology. When it comes to the social expression of this tendency, regularity ceases. Sometimes the value of the special day is virtually identical among unconnected social groups, such as the Mayas and Egyptians; sometimes it is diverse, as between them and ourselves; and sometimes the value wholly disappears, as in Armenia. Parallelism in any matter of civilization is never complete and perfect, just as culture elements rarely spread far or long without modification.