Browse Prior Art Database

Era Date Support for Single and Multiple Calendar Cultures

IP.com Disclosure Number: IPCOM000107265D
Original Publication Date: 1992-Feb-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 5 page(s) / 152K

Publishing Venue

IBM

Related People

Bunton, RM: AUTHOR [+6]

Abstract

A method to support single or multiple calendars along with single or multiple eras, on a single date line, is disclosed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 39% of the total text.

Era Date Support for Single and Multiple Calendar Cultures

       A method to support single or multiple calendars along
with single or multiple eras, on a single date line, is disclosed.

      This invention supports:
o    The association of an era with a date.
o    Collation of era dates correctly, chronologically.
o    Multiple eras.
o    Multiple era and calendars, whether or not they are
synchronized.
o    Ascending and descending eras.
TERMINOLOGY
JOSEPH SCALIGER--In 1583 Gregorian, Joseph Scaliger developed a
system to place all known dates of past and present civilizations on
a time- line that was chronologically correct.  A system of a
monotonic progression of days and fractions of day from some
arbitrary point in time was used.
DATE LINE--A line consisting of the integer numbering system in which
each number represents a solar day.
MODIFIED SCALIGER NUMBER--A number which represents a count of solar
days from an arbitrary known origin on the date line. The number does
not account for fraction of days.
CALENDAR--An algorithm which converts a given cultural representation
of a date to a modified Scaliger number.
DATE STRING--A character string of symbols that represents a given
solar day on the date line.
HISTORICAL CALENDAR CALIBRATION TABLE (HCCT)--HCCT defines a date
line that describes when history starts and ends, and a place holder
indicating when each type of calendar format takes effect within that
date line.
ERA DEFINITION TABLE--The era definition table associates a set of
eras to the date line.
CALENDAR CODE--The calendar code is the linkage that the data base
management system (DBMS) uses to associate a particular date string
to a historical/cultural calendar on the date line.
ERA CODE--The era code is the linkage that the DBMS uses to associate
a particular date string to an era define on the date line.

      To make the association between the date line and an era date
string, this invention introduces an era code which represents the
era and its name, and an era definition table which defines a given
set of eras on the date line.

      The era code along with the calendar code and date string make
up a fully qualified date.  The following is a pictorial
representation of the end user date that is interpreted and presented
across the DBMS interface.

      The era definition table entry defines: The era name associated
with the date line, the starting and ending point of an era with
respect to the date line, and an indication of whether the era is
ascending or descending in terms of years.  The following is a
pictorial representation of an era definition table entry.

      The following is a list that further defines the era definition
table:
      The start of an era is defined by a modified Scaliger number.
      The last table entry will be used for the rest of the date
line.
      When a descending era table entry is defined, a succeeding
entry must exist...