PETER A. PECK U. S. Army Chemical Corps Proving Ground, Dugway, Utah
FAR
from the realm of the usual applications of punched cards in science, business, and industry is the punched card perpetual calendar. Frivolous by its nature, it nevertheless exemplifiesthe techniques of punched cards, and a person unfamiliar with punched cards might well he introduced to a helpful instrument via this novelty. Constructed from only thirty-five 98-hole (minimum) single row edge punched cards, the punched card perpetual calendar can be a handy desk companion; or if made from larger cards, i t can be a useful wall calendar. Figure 1 illustrates the basic card required. The cards may be of any size or shape, and cards having more than 98 holes may be employed, for the excess of holes above this number will remain unused. The cards are numbered consecutively, and upon the face of each is placed one of the twenty-eight possible monthtypes (there are seven 28-day months, seven %day months, seven 30-day months, and seven 31-day months). Duplicate cards are prepared for each of the seven 31-day month-types. The cards are then coded, by means of notching, according to the scheme of Table 1. With the aid of Table 2, the cards are ready for use.
Figum 1.
Th. Basic C u d
In Table 2, each year is assigned a year-type letter. Years beyond the upper limit of the table may be brought into range by subtracting from them a whole number multiple of 400 (2356 is equivalent to 1956; 3098 is equivalent to 1898). It is to be pointed out that the perpetuity of the calendar is valid only for the period from September 14, 1752 (the date of the inception of the Gregorian calendar in the United States) to the year A.D. 4000. This lack of perpetuity is not
TABLE 2
175 176 in 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194
VOLUME 34, NO. 12, DECEMBER, 1957
YEAR
TYP -
0 1 2 3 4 5 6 7 8 9
-
0 1 8 3 4 5 6 7 8 9
A F N H M D L F K B J D I N H B G L F N E J D L C H H J A F N H M D L F K B J D I N H B G L F N H B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H K D L F K B J D I A H B G L F N E J D L F N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D
195 196 197 198 199 200 201 202 203
L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B J D L F K B J D I N H B G L F N E J D L C H B J A F N H M D L F K B J D I N H B G L F N E J D L C H B J
2w
205 206 207 208 209 210 211 212 213 214 215 -
611
inherent in the cards, but rather it lies in the mathematics of the calendar system. With an appropriate expansion of Table 2, for all practical purposes unnecessary, the calendar can he made perpetual in every sen,:e of the word. To select from the thirty-five cards the calendars of the twelve months of any desired year: In the year-type selector section, pass the sorting needle thru the hole designated by the year-type letter of the desired year. The cards which drop when the needle is lifted are those
desired. To select from these twelve cards the calendar of any particular month: I n that month selector section whose designating pair of letters contains the year-type letter of the desired year, pass the sorting needle through the hole specified by the month desired. As before, the card which drops when the needle is lifted is the desired calendar. The adaptation of the common calendar to punched cards is but one more example of the versatility of punched cards.
JOURNAL OF CHEMICAL EDUCATION
