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Publication numberUS896255 A
Publication typeGrant
Publication dateAug 18, 1908
Filing dateMar 15, 1907
Priority dateMar 15, 1907
Publication numberUS 896255 A, US 896255A, US-A-896255, US896255 A, US896255A
InventorsWilliam B Summerall
Original AssigneeWilliam B Summerall
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Perpetual calendar.
US 896255 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

No. 896,255. PATENTED AUG. 18, 1908;




PATENTED AUG. 18, 1908.



a \w T QL Q QDNO ROD @ZZZ 723452;?7277207 A Z;

A TTOR/VE 1 5 I of the surface of the calendar.



Specification of Letters Patent.

Patented Aug. 18, 1908.

Application filed March 15, 1907. Serial Il'o. 362,523.

To all whom it may concern:

Be it known that 1, WILLIAM B. SUMMER- ALL, a citizen of the United States, residing at Atlanta, in the county of Fulton and .State of Georgia, have invented a new and useful Perpetual Calendar, of which the following is a specification This invention relates to perpetual calendars, and has for its principal object to provide a device of simple construction which may be used as an ordinary month or annular calendar, and which may, also, be used to determine the day of the week of any desired date, the tables being arranged in the present instance to cover the entire period up to the year 2799.

A further object of the invention is to provide a calendar so arranged as to correctly show dates of all years, both common and leap years, of both the Julian and Gregorian calendars.

A still further object of the invention is to provide a device of this class which will occupy a small space and which may be util ized as an ink well, paper Weight, or the like.

With these and other objects in view, as will more fully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in .the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of construction may be made Within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings :-Figure 1 is a perspective view of a calendar arranged and constructed in accordance with the invention. Fig. 2 is a transverse sectional elevation of the same with the parts detached from each other. Fig. 3 is a sectional plan view of the device. Fig. 4 is a development Fig. 5 shows two sets of panels, the ring and body portion having been adjusted to each other for the purpose of determining a date in the nineteenth century. Fig. 6 is a similar view showing a further adjustment and representing monthly calendars for April, July, January and October of common years, and

' September, December, January, April and July of leap years during twenty-eight years of any century. -Figs. 7, 8 and 9 are detail views, illustrating portions of the tables transposed. Fig. 10 is a view similar to Fig. 3 showing a circular support and ring instead of the septangular form shown in Figs. 1 and 3.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the draw- 111 s.

The construction of the bod y portion of the calendar is such that it may be employed as an ink well, paper weight or the like, although this is not material. The body portion comprises a hollow body 10 of which the bottom may be either closed or opened, and this body portion is either septangular or cylindrical in form, the upper portion of the body being somewhat reduced, forming an abrupt shoulder 12 against which may be seated an upper adjustable ring 13 of a contour corresponding to that of the body portion and arranged to fit snugly against the shoulder when adjusted to place.

Where the'septangular form is adopted, there is no danger of the upper ring moving independently of the body portion, and this upper ring may be held down in place by a suitable cap or cover piece 15.

It is obvious that the two main sections of the calendar may be otherwise connected, and fastenings of any character employed for preventing independent movement of either section from adjusted position.

The calendar characters as applied to the body portion and ring are shown more clearly in Fig. 4, which represents a development of the outer surface of the calendar.

The upper See. I comprises two horizontal rows, containing the years of a century from O0 to 99, inclusive, and also the abbreviations N. S., (for new style), and O. S., (for old style), and the 00 repeated once again. One 00 is for century years of the new style calendar, that is to say, covering the period following March 20, 1582, and the other 00 being for century years of the old style calendar prior to March 12, 1582. from 1 to 50 inclusive and the abbreviations N. S. and O. S. are placed in the upper row, while the two 00 and the year numbers from 51 to 99, inclusive, are placed in the lower row of Sec. I. If the covering be of sufiicient size only one row will be necessary for the purpose. The numbers are recorded from left to right in sequential order as they relate to the index days in Sec. VI, as will more fully hereinafter appear.

The year numbers for leap years.

In Sec. II are shown two superposed rows, each of which contains the names of the months of the year, the sequent number of each month and the number of days in each month, it being noted, for instance,that the space which bears the abbreviation Jan. also contains the numerals 1 and 31, signifying the number of the month and the number of days therein. The upper row of month names and theirattributes are recorded from left to right in the order in which they occur during leap years, and are to be used The month names in the lower row of Sec. II are likewise, arranged for common years and are to be used for common years.

In Sec. III is a row containing the names of the days of the week repeated seven times in sequence from left to right, starting in each case with Su. and ending with Sa.

Sec. IV is a broad row containing the numbers from 1 to 31 inclusive, repeated seven times in sequence from left to right.

Sec. V consists of two horizontal rows containing the century years from 00to 2700, inclusive. The upper of these rows contains the century years of the old style or Julian calendar, namely from 00 to 1500, inclusive, all of which were leapyears, every year number divisible by four without remainder being a leap year according to the Julian calendar. The lower row contains the century numbers from 1600 to 2700, inclusive, of the new style or Gregorian calendar, only three of which are leap years, namely, 1600, 2000 and 2400, it being of course well known that in the new style calendar only those century years divisible by 400 without remainder are leap years.

In Sec. VI is a row containing the names of l the days of the week recorded in sequence from left to right. This row is the index of the day of the week on which January 1st occurred or will occur'in any given year, as will more fully hereinafter appear.

All of the foregoing horizontal sections are divided perpendicularly into seven prime sections or panels on accentuated perpendicular lines running through from top to bottom, and where the septangular form is used there is a separate section or panel for each face of the septum.

Each of the panels contains at the bottom, in section VI, the name of a dayof theweek, which, as has been stated, is an index of the day of Week on which January 1st of any year occurs. Taking one of these days, say Friday, as the starting point, we record in the upper row of Sec. V the old style century years 600 and 1.300; in the Saturday panel of this row are recorded the century years 500 and 1200; in the Sunday panel are 400 and 1100; in the Monday panel, 300 and 1000; Tuesday panel 200 and 900, Wednesday panel 100 and 800, and 1500; Thursday panel 100, 700 and 1400, all of which were leap years according to the Julian calendar. Again, beginning with Friday, we record in the lower row of Sec. V the new style calendar centuries ;under Friday, 1700, 2100 and 2500; under Saturday, 1600, 2000 and 2400 in the Sunday panel no century years are recorded; under Monday are 1900, 2300 and 2700; Tuesday blank; Wednesday, 1800,

2200 and2600; Thursday blank. All of these are common years, with the exception of the years 1600, 2000 and 2400 which, being divisible by 400 without remainder,

are leap years according to the Gregorian each of the panels thirty-five spaces, and in these, or as many of them as are necessary,

the numbers from 1 to 31 inclusive are marked from left to right, and from to to bottom. It isimmaterial at which pane we begin the record. The point to be observed in the arrangement under consideration is to begineach series ofthese numbers one space to the right of the beginning of the series receding, with the result that each space 0 the uppermost row will in turn contain the Fig. 1. We thus have these seven series of numbers beginning in the Friday panel in the third space of Sec. IV in the Saturday panel in the fourth space; in the Sunday panel in the fifth space; in the Monday panel in the sixth space; in the Tuesday panel the 7th space; in the Wednesday panel the first space, and in the Thursday panel the second s ace. Again beginning with Fridays pane we record in Sec. III the names of the days of the week from left to right, beginning with Sunday. This is repeated in sequence in each panel, and each of the panels of Sec. III is subdivided perpendicularly into seven equal spaces coinciding with the spaces in Sec. IV. Beginning a ain with the Friday panel, we record in the lower row of Sec. II from left to right the names of the months and their attributes as they occur in common years, thus we have in the Friday panel Jan. 131; Oct. 1031. In the Saturday panel is marked May 5-31. In the Sunday panel is marked August 831 in the Monday panel is marked Feb. 2-28; Mar. 33].; Nov. 1130; in-the Tuesday panel is marked June 6-30 in the Wednesday panel is marked Sep. 930; Dec. 12'31. In the Thursday panel is marked Apr. 430; Jul. 731. Again beginning with Friday we record in the upper row of Sec. II the months and their attributes as they occur in leap years. in this row in the Friday panel J an. 131 Apr. 4-30 and Jul. 731 in the Saturday We thus have 69, 75, 86, 92 and 97.

panel October 1031 in the Sunday panel May 5-31; in the- Monday panel Feb. 229, Aug. 831; in Tuesday panel Mar. 331 and Nov. 11-30; in Wednesday panel June 6-30 and Thursday panel Sep. 930 and Dec. 1231. This row of month names must be used for leap years. Again beginning with Fridays panel, we record in this panel of Sec. I, upper row from left to right, N. S., 6, 12, 17, 23, 34,40, 45; in the lower row 00, 51, 62, 68, 73, 79, 90 and 96. In the Saturday panel the upper row contains 1, 7, 18, 24, 29, 35, 46; in the lower row, 52, 57, 63, 74, 80, 85, 91. In the Sunday panel, upper row, 2, 8, 13, 19, 30, 36, 41 and 47; lower row, 58, 64, In the Monday panel, upper row, 3, 14, 20, 25, 31, 42, 48; lower row, 53, 59, 70, 76, 81, 87 and 98. Tuesday )anel, upper row, 4, 9, 15, 26, 32, 37, 43, lower row, 54, 60, 65, 71, 82, 88, 93 and 99. Wednesday panel, upper row, 10, 16, 21, 27, 38, 44, 49; lower row, 55, 66, 72, 77, 83, 94. Thursday panel, upper row, 5, 11, 22, 28, 33, 39, 50, 0. S.; lower row, 56, 61, 67, 78, 84, 89, 95, 00.

A characteristic must be applied to the numbers of the century years that are leap years; to the'years of a century that are leap years, and to the names of the months and their accompanying sequent numbers and the number of days that are used for leap years and to the designations O. S. and 00 that are used for leap year centuries, in order to differentiate them from' common year characters. Therefore, leap year characters may be red or black, with white or open type characters, while the characters of the common years are printed in black on a white or other distinguishing background.

The calendar characters as described in the above arrangement are divided into two parts by the horizontal line which divides the Secs. II and III, the Sec. I and II being applied to the outer surface of the movable ring, and the remaining sectionsbeing car ried by the body portion of the calendar.

The following demonstrations will illustrate the adjustments and use of the calendar. Secs. V and VI are inseparable and absolutely fixed. Therefore, without any adjustment of parts, we have shown by these two Secs. V and VI the day of the week on which Jan. 1st occurred, or will occur, for any even century year, namely 600, 1300, 1700, 2100, all had, or will have Friday for January 1st. This date, Jan. 1st., falls on Saturday in the years 500, 1200, 1600, 2000,-

2400; on Sunday in the years 400, 1100; on Monday in the years 300, 1000, 1900, 2300, 2700; on Tuesday in the years 200, 900; on Wednesday in the years 100, 800, 1500, 1800, 2200, 2600; on Thursday in the years 00, 700, 1400. 7

Suppose it be desired to determine the day of the week of April 29, 1867. The day on which January 1st occurred, or will occur is in all cases the starting point in determining the day of any date, as in all adjustments the calendar is at one and the same time a J anuary 1st century calendar for two or more centuries, and an annular calendar for a certain number of years in these centuries. All of this will be shown in determining the day of the week of April 29, 1867. The first step is to adjust the upper ring so that 1800, (Sec. V) coincides with 00 N. S. Sec. I. It will be observed that 1800 is a common year, therefore in black, and it is adjusted to the common year 00, also'in black. As the calendar now stands it is a January 1st century calendar for 500 years, namely for the years 1800 to 1899, inclusive; 2200 to 2299 inclusive; and 2600 to 2699 inclusive, this covering the three centuries that begin as common years, and by noting the 00 of O. S. for use in leap year centuries, it will be observed that it coincides with the leap year centuries 200 and 900, and therefore" this same adjustment gives us the date of January 1st for 200 to 299 and 900 to 999, inclusive. Therefore, beginning with 1800, 2200 and 2600, each of which conforms to the 00 N. S. and has Wednesday for January 1st, the years 6, 12, 17, 23, 34, 40, 45, 51, 62, 68, 73, 79, 90 and 96, of each of these centuries has Wednesday 'for January 1, and whereas the leap year century years 200 and 900 had Tuesday for J anuary 1st, these century years conforming or coinciding with the 00 O. S. the years of these centuries as above named in the- Wednesday anel had Wednesday for January 1st. Li (ewise the years of each of these five centuries, (SecQI) that are in the Thursday panel had, or will have, Thursday for January 1st, and this is true of the years in the panels of each index day around the calendar. It is true of leap years as well as of common years.

Thus far it will be seen that the calendar as set shows at a glance the day of the week of January 1st for each 500 years. It will be seen further that Jan. is marked in Sec. II for use in both leap years and common years as they are coincidental, having Tuesday for the first day of the month when the parts are adjusted as shown in Fig. 4, Sec. IV showing the numeral 1 under Tu. in Sec. III.

To determine which of the years of the foregoing five centuries had Sunday for J anuary 1st, reference is now made to the Sunday panel, and it is found in See. I that fifteen different years have Sunday for January 1st. Therefore the calendar as set is a month or annual calendar for each of these different'years in each of the above five centuries, that is to say, they have the monthly or annual calendar for the leap years 4, 32, 60 and 88 by using the upper or leap year row of months in Sec. II, and we have the monthly, annual calendar for the common years 9, 15, 26, 37, 43, 54, 65, 71, 82, 93 and 99 by using the lower or common year row of months in Sec. II. The day of any date in any of these years, whether leap year or common year, can be seen at a glance without further adjustment.

To recapitulate then, the calendar as shows the day of the week of January 1st. for each of five hundred different years, both leap years and common years, and annual or monthly calendars for fifteen different years in each of these five centuries, or a total. of seventy-five different years, both leap and common.

In proceeding to determine the day of the 1 week of April 29, 1867, the calendar is set for the hundred years beginning with 1800, that is to say, the upper ring is so adjusted that that portion of its panel bearing N. S. is moved into alinement with that portion of the stationary panel bearing 1800 in the lowermost row of Sec. V. The year numbers in See. I are then consulted until the panel containing 67 is found, and then looking at the day name in the bottom Sec. VI it is found that January 1, 1867, fell on Tuesday. The upper ring is then adjusted so that the panel bearing Jan. in Sec. II will be moved into alinement withthat portion of the stationary panel that has Tuf Sec. III, coinciding with the numeral 1 of Sec. IV. Then as 67 is a common year, it will be seen that April, lower row of Sec. II, has its 29th day on Monday, (Fig. 6).

As a further example, we will proceed to determine the day of the week of October 12, 1492. The upper ring is adjusted so that 1400 in the upper row of Sec. V, being a leap year, as shown in the open or block figures, coincides with 00 O. S. for leap year centuries in the upper row of Sec. I. It will be seen that 92 in See. I is then in alinement with. the lowermost panel bearing the word Sunday, and indicating that January 1st., 1492, fell on Sunday. The upper ring is now adjusted, so that Jan. in block letters,

Sec. II, coincides with that panel in the body portion of the panel having Six. in Sec. III coinciding with numeral 1in Sec. IV. We then have a complete annual calendar for the year 1492, with January 1st. on Sunday. It will be observed that 92 is a leap year. Therefore, to determine any day in this year use the leap year row or set of months in Sec. II, and it will be seen that October 12, 1492 fell on Friday.

Secs. V and VI, which are fixed in their mutual relations, refer only to Sec. I under any of the groupings illustrated, their use being solely to determine the day of the week of January 1 of any given year, and to indicate whether such year is a leap year or common year. This being true, it will be set seen that several transpositions of the differ-- ent sections may be made, as will be seen on referenceto Figs, 7, 8 and 9.

In the arrangement shown in Fig. 7 the upper adjusting ring carries Secs. VI, V and indeX days at the bottom, while in Fig. 7 this i order is reversed.

In the arrangement shown in Fig. 8, Secs. I and III are placed on the. adjustable ring, and Secs. IV, II and V and VI are on the lower or stationary body portion.

In Fig. 9 the Secs. VI, V and III are placed I on the upper adjustable ring, and Secs. IV and II and are on the lower or stationary body portion. The result of transposing Sec. III from the stationary body portion to the ring will be to cause the names of the days of a week in Sce. III to shift their relative positions as regards Sec. IV when the calendar is adjusted for a great majority of years. While in these two latter. groupings the accuracy of the calendar is in no wise diminished, this form is not so satisfactory as that shown in the original, and that shown in Fig. 9 is not as satisfactory as that shown in Fig. 8.

The Secs. II, III and IV are mutually related according to the different groupings as shown in the original and in the transpositions, Figs. 7, 8 and 9. In the arrangement shown in Fig. 7, Sec. II of the adjustable ring refers only to Secs. III and IV of the body of the calendar, and in the arrangement shown in Figs. 8 and 9 Sec. III of the ringrefers to Secs. IV and II of the body of the calendar. The use of these Secs. II, III and IV is solely for the production of an annual calendar for either leap years or common years. VI may be dropped from the calendar, thus leaving Secs. II, III and IV which produce an annual calendar for any current year, whether it be a'leap year or a common year.

The upper or leap year circle of months of Sec. II may be omitted from the calendar, but in so doing it will be necessary to readjust the calendar for the first day of March in all leap years, by turning the upper ring oneseventh of a revolution to. the right, thus causing March to make its advent one day later in a leap year. By making this adjustment for leap years, the accuracy of the The above being true, Secs. I, V and calendar is in no wise diminished. The remethod of computing time, as it is readily;

apparent that by adding four hundred years,

or any multiple of four hundred years to any century year recorded in the lower circle of Sec. V, the century indicated as the result of such addition will fall in the same prime segment as is the recorded century-that takes part in the addition, and the date of January 1st of any year of such indicated century can be as readily determined as is the case with any year of the recorded century. For example, by adding four hundred to twentyfive hundred, the highest century recorded in Fridays panel, I get twenty-nine hundred, which century belongs -in this panel. So likewise would nine times four hundred, or thirty-six hundred, which, being added to twenty-five hundred gives sixty-one hundred. Twenty-nine hundred and sixty-one hundred would become year centuries as is twenty-five h'undred,the century that participates in the addition. The same is true of leap year centuries in the lower circle of Sec. V. Four hundred added to twenty-four hundred will give twenty-eight hundred, the leap year century belonging to the Saturday panel, as does twenty-four hundred. So,

also, thirty-six hundred added to twenty four hundred will give six thousand, theleap year century falling in centuries panel.

I claim A perpetual calendar comprising a series or plurality of hollow members or sectionssuperposed with relation to each other, the bottom one being stepped upon its exterior surface, the intermediate one forming an annulus and encompassing theuppercontracted portion of said bottom member or section, and the top member or section having its lower contracted portion inserted through said annulus and entering said bottom section, said annulus and bottom member being divided into a predetermined number of panels containing suggested indicia of the days of the week, also numerals indicating century years, said numerals being divided in accordance with the name of the day on which January 1 occurred, or will occur in the respective years, said calendar also bearing numerals from one to ninety-nine inclusive, said numerals being apportioned among the several panels in groups of irregular sequence so that the number of each year shall be in thatpanel bearing the dayname on which January 1st of that year occurred or will occur.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two Witnesses.



Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5765145 *Jul 28, 1997Jun 9, 1998B. Edward Shlesinger, Jr.Method for performing date operations on date fields spanning several centuries
Cooperative ClassificationG09D3/06