Perpetual calendar
BACKGROUND OF THE INVENTION 
     The present invention refers to a perpetual calendar, for the use preferably on desks of offices, and which presents a particular constructive disposition, such as will be explained in the following description. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, said perpetual calendar comprises a vertical support, provided below with an extension, which forms its bearing surface. This support is formed by two lateral vertical prismatic members, erected parallelly and backed by a posterior plate, which forms, together with a transparent frontal sheet, a rectangular flattened parallelopiped, with its top side opened. The frontal transparent sheet has near its upper edge, a line of indicia denoting the week&#39;s days. 
     Within the parallelopiped, are introduced seven long prisms of a square section, showing on their lateral sides several numbers, forming a column and corresponding to some days of the month. These long prisms are located closely next to each other in the described lodging, and the length of each of the seven juxtaposed prisms corresponds to the length of the lodging, while the combined width of their equal sides, corresponds to the width of the lodging and, therefore, once located in their places, they rest duly immobilized inside of the mentioned lodging. 
     For being supported on the desk, the lower end of a lodging is provided with a curving leading to an extensive horizontally directed plate, which forms a support, together with the curviform extension of the posterior backing plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In order to make the present invention clearly comprehensable and make it easy for applying in practice, it is represented in its preferable form of execution in the attached drawings, in which: 
     The FIG. 1 represents a perspective view of calendar. 
     The FIG. 2 represents a frontal view of same. 
     The FIG. 3 represents a view of a vertical section of the calendar&#39;s lodging, indicating separately where must be introduced one of the square long prisms, with the numbers of some days of the month, marked on its lateral side. 
     The FIG. 4 represents a view in plan of the calendar. 
     In said figures the same numbers of reference indicate the same parts. 
    
    
     SPECIFIC DESCRIPTION OF A PREFERRED EMBODIMENT 
     As regards the drawings - 1 indicates the calendar&#39;s support, provided on each of its sides by the straight upright members 2 and 3, parallel in part with them, backed and connected to a rectangular plate 4. 
     On the front side of the mentioned lateral members, a transparent sheet 5 is fixed with screws; on the top part of this sheet 5, near its upper edge, are engraved the names or the abbreviations of the seven weekdays. 
     Between the backing plate 4 and the frontal transparent sheet 5 is formed an enclosure 7 having a shape of rectangular flattened parallelopiped, which comprises the lodging for locating the corresponding series of long rectangular prisms 8, (seven in total), on which lateral sides are engraved the columns of numbers, indicating the days of the month. 
     As it can be observed in FIG. 4, said prisms 8 are located next to each other -- in juxtaposed relation -- filling all the space of the enclosure 7, because the length of same is practically equal to the length of each of the seven square sections of the prisms 8 and its width is equal to a combination of the widths of a single side from each of the prisms 8. 
     For securely footing the body 1 of the support, its lower zone is extended in a curve leading to a bearing plate 9, which, for better stability, extends to the end of an extension 10 of the rear backing plate 4. Said bearing plate 9, apart from being a good support, can also be used for supporting writing utensils. 
     The numbers engraved on the faces of the long prisms 8, are disposed differently on each prism, in such a way that the prisms can be duly located every month, in order that the engraved numbers indicate correctly the corresponding week&#39;s days, marked on the transparent sheet 5. 
     It is evident that the modifications of details can be introduced in the calendar, if they are forming part of the scope of the present invention, which is clearly determined by the clauses of the claims, which are following the present description.