GB1222556A - Improvements in or relating to calendars - Google Patents

Abstract

1,222,556. Perpetual calenders. A. A. DICKSON. March 12, 1969 March 23, 1968], No.14135/68. Heading G3T. A perpetual calender for indicating dates according to the Julian and Gregorian systems comprises, members 1, 2, e.g. a sheet 2 slidable within a cover 1, the member 2 having arranged at unit intervals, in the direction of relative movement of the members 1, 2, columns 5 of indications of all the years of a century, arranged in solar cycles of 28 years, and indications 10 of days of the week, and the member 1 having seven century indexing positions 3 arranged to co-operate with the year indications 5, and spaced apart by seven or a multiple of seven unit intervals and associated with the positions 3, and two sets of century indications, arranged as to the centurial terminal days, and in seven-century Julian cycles and four-century Gregorian cycles, respectively. The member 1 also carries monthly calendar blocks 7 each displaying dates in seven columns associated with different days of the week, cooperating with the day indications on the member 2, the arrangement being such that when a selected year indication 5 is aligned with a selected century indicating position the appropriate terminal day indication will be aligned with the calendar block column containing the terminal date of a year, the remaining calendar block columns then being associated with the current day indications. The member 1 also has key indexing positions 4 and 8 co-operating with centurial terminal day indicia 6 and 9, respectively, on the member 2. A further embodiment comprises a third member which may be integral with the member 2 and has Golden Number and Epact cycle indicia co-operating with indexing positions on the member 1, whereby the calendar may be utilized to indicate the date of Easter Day in any selected year.