Abstract: A perpetual calendar system comprising: a first array of letter positions, each letter position in the first array denoting a position corresponding to a digit in Gregorian numerical system; a second array of numbers corresponding to digits in the Gregorian numerical system; and a third array of symbols comprising a plurality of groups of years, wherein each group corresponds to a related letter position and a related number in the first array and the second array respectively, such that a combination of: the related letter position from the first array, the related number from the second array, and the plurality of groups of years in the third array is used to locate a calendar for a year of interest, and wherein the combination corresponds to a page index in the perpetual calendar system constituted by a plurality of pages, each page having a calendar identified by the corresponding page index.

Abstract: A hub is formed with a lower extent having a first diameter, an intermediate extent having a second diameter, and a circular upper extent having a third diameter. A circular disk has an upper surface with indicia, a lower surface with an attachment component, and a hole with a diameter essentially equal to the second diameter for being received by the hub. A pointer has a first free end and a first securement ring having an interior diameter essentially equal to the third diameter and an exterior diameter essentially equal to the second diameter. The first securement ring is in sliding contact with the intermediate extent of the hub.

Abstract: A perpetual calendar wheel chart for determining the calendar for a particular year past, present, or future is comprised of two wheel members adapted to rotate about a common center. The first wheel member has in its center indicia representing the tens and ones digits of the year and has around its circumference indicia representing the day of the month. The second wheel member atop the first wheel member is generally transparent and has in its center indicia representing the hundreds and thousands digits of the year for aligning with the ones and tens digits of the year indicia of the first member and has around its circumference twelve transparent windows representing the months of the year that align with the day of the month indicia of the first member to indicate the calendar for a particular year.

Abstract: A gestation calendar for use by an expectant mother. A first disk has first indicia corresponding to days of a calendar year. A second disk is pivoted concentrically to the first disk and has second indicia defining successive weeks of a gestation term and associated information. The information includes imagined statements by a fetus representing its development during the time intervals, with corresponding information relating to prenatal health care for the mother. When the first and the second disks are positioned so that an index mark of the second indicia is aligned with a start date of the mother's last period in the first indicia, the development of the fetus at a certain date during pregnancy along with the corresponding prenatal health care information are conveyed by the information associated with that time interval which is aligned with the certain date in the first indicia.

Abstract: A gestation calendar for use by an expectant mother. A first disk has first indicia corresponding to days of a calendar year. A second disk is pivoted concentrically to the first disk and has second indicia defining successive weeks of a gestation term and associated information. The information includes imagined statements by a fetus representing its development during the time intervals, with corresponding information relating to prenatal health care for the mother. When the first and the second disks are positioned so that an index mark of the second indicia is aligned with a start date of the mother's last period in the first indicia, the development of the fetus at a certain date during pregnancy along with the corresponding prenatal health care information are conveyed by the information associated with that time interval which is aligned with the certain date in the first indicia.

Abstract: A calendar indicator includes a date disc, a week disc and an indicator member. The date disc is equally divided into 28 date indicating segments. The date disc further has 28 numerals, from "1" to "28", respectively provided in sequence on the 28 date indicating segments of the 28 date sectors. The three adjacent date indicating segments having the numerals "1", "2" and "3" provided thereon respectively form a first, a second and a third sub-segment. Three numerals including "29", "30" and "31" are respectively provided on the first, second and third sub-segments. The week disc which is coaxially and rotatably mounted on the date disc is equally divided into 28 week indicating segments. The indicating member is rotatably mounted on the week disc for indicating what date and day of week is today. Whereby the user may easily find out what day is today and the day of week of today from the calendar indicator of the present invention.

Abstract: A multi-dimensional calendar (10) for indicating the day, date and month. The multi-dimensional calendar (10) includes three disks (28), (30) and (32). The first disk (28) has a circumference and includes indicia indicative of the date printed about a periphery thereof. The second disk (30) has a circumference of a size smaller than the circumference of the first disk (28) and includes indicia indicative of the month printed about a periphery thereof. The third disk (32) has a circumference of a size smaller than the circumference of the second disk (30) and includes indicia indicative of the day printed about a periphery thereof. A platform (12) retains the first, second and third disks (28), (30) and (32) thereon, whereby the second disk (30) is positioned between the first and third disks (28) and (32). A first gear apparatus (64) automatically rotates the first disk (28) a first predetermined distance after expiration of a first predetermined period.

Abstract: A perpetual calendar has a top sheet member having several viewing apertures formed therein. The top sheet displays on a top surface thereof in seven vertical columns the dates of the month from one to twenty-eight. One of the apertures is positioned to display up to three additional dates of the month after the numeral 28. An intermediate substrate layer is disposed beneath the top sheet and is rotatably mounted thereto. This substrate displays on a top surface thereof data for indicating days of the week, which is displayable through one of the apertures. A bottom substrate or sheet is disposed beneath the intermediate substrate and is rotatably mounted with respect to the other two substrates or sheets. This substrate layer displays on a top surface thereof the 12 months of the year and also month ending date or dates for months having more than 28 days.

Abstract: A calendar including a first disk and a second disk. The second disk is connected to and rotatable concentrically relative to the first disk. The first disk includes a window and indicia adjacent to the window representing the various days of the week. The first disk further includes indicia indicating various months of the year and lead lines which function as pointers. Thus, the user may select, by using the pointers, a desired year from a table or a list of a plurality of years appearing on the second disk. This configuration allows the user to easily select a predetermined year by means of a pointer. The second disk further includes a day number grid, the dates ranging from 1 to 31. When the second disk is rotated relative to the first disk, the day grid draws an orbit and the grid is located below the window of the first disk. Consequently, when a predetermined year with respect to a predetermined month is selected, the window displays a corresponding calendar month.

Abstract: A perpetual calendar is disclosed which contains base and top members and a rotating disk member in between. The top member has two arcuate window openings, through one of which is seen the days of the month, and through the other of which is seen numerical indicia corresponding to a particular year desired. The back of the base member carries a key to the year indicia in matrix form which is accompanied by instructions for its use.

Abstract: Universal round calendar of a simple design which may be employed for various calendar systems. It provides traditional sequences of data and their intelligible and quick readjustment on another desired date. The universal round calendar may be employed as a part of a pocket watch or wrist watch without the necessity of any adaptation of the design of the watch mechanism, or it may be used as a complement of electronic digital watches. It also provides a direct function coupling between a calendar and a watch. The calendar, according to the invention, consists of two mutually revolving discs carrying indication marks for calendar data, the mutual position of which corresponding with the desired month in any range of years, is set up according to the code marking of the desired actual month.

Abstract: A day and date indicator comprises a carrier structure which supports for rotation a flat, annular date disc and, within a recess in said date disc, a flat annular day disc. The inner peripheries of the two discs are provided with gear teeth that are adapted to be engaged by a cam driven by the clockwork mechanism and operative to advance each disc by a single increment once each day. The carrier structure is fabricated of a plastic material and includes resilient clamps and projections for attaching the carrier structure to the clockwork housing, integral resilient detents engaging the day and date discs to hold the discs in position when they are not being advanced by the cam, and a sleeve-like collar surrounding the indicator shaft of the clockwork mechanism for attaching the indicator to the housing of the clock.

Abstract: A calendar comprising a date disk and a week disk which are rotatably coupled with each other. The date disk has date figures and the week disk has week indicating letters. The calendar has further month indicating letters and formations for bringing unnecessary month indicating letters into the invisible state. The date disk and the week disk may be corresponded according to the selected month by relatively rotating both disks and selecting the month indicating letter.