A Definition of Year 2000 conformity requirements
(The following document is included in its entirety to comply with copyright provisions for the reproduction of SAA/SNZ MP77:1998 A Definition of Year 2000 conformity requirements.)
This Miscellaneous Publication addresses what is commonly known as year 2000 conformity (also known as century or millennium compliance). It provides a definition of this expression and sets out requirements for equipment and products which use dates and times.
This Miscellaneous Publication is equivalent to British Standards Institution (BSI) document DISC PD 2000-1, A Definition of Year 2000 Conformity Requirements, but has been re-keyed to facilitate reproduction on the Internet. The only variations from the BSI document are the deletion of the list of British contributing organisations from the third paragraph of the Introduction, and the numbering of the clauses.
This document replaces the previous, initial version, but does not change its requirements. Additional information has been provided in the Amplification which will assist in the interpretation of the Definition and the four Rules.
While every care has been taken in developing this Miscellaneous Publication, Standards Australia, Standards New Zealand, BSI and the contributing organisations accept no liability for any loss or damage caused, arising directly or indirectly, in connection with reliance on its contents, except to the extent that such liability may not be excluded at law. Independent legal advice should be sought by any person or organisation intending to enter into a contractual commitment relating to year 2000 conformity requirements.
NOTE: Additional information on year 2000 conformity is available in--
2. THE DEFINITION
Year 2000 conformity shall mean that neither performance nor functionality is affected by dates prior to, during and after the year 2000.
(i) General explanation
Problems can arise from some means of representing dates in computer equipment and products and from date-logic embedded in purchased goods or services, as the year 2000 approaches and during and after that year. As a result, equipment or products, including embedded control logic, may fail completely, malfunction or cause data to be corrupted.
To avoid such problems, organisations must check, and modify if necessary, internally produced equipment and products and similarly check externally supplied equipment and products with their suppliers. The purpose of this Miscellaneous Publication is to allow such checks to be made on a basis of common understanding.
Where checks are made with external suppliers, care should be taken to distinguish between claims of conformity and the ability to demonstrate conformity.
Specific comment is as follows:
(b) Rule 1
NOTE: This refers to normal operation and does not prevent testing.
(c) Rule 2
(d) Rule 3
(a) Explicit representation of the year in dates: e.g. by using four digits or by including a century indicator. In this case, a reference may be inserted (e.g. 4-digit years as allowed by AS 3802--1989 ) and it may be necessary to allow for exceptions where domain-specific Standards (e.g. Standards relating to Electronic Data Interchange, Automatic Teller Machines or Bankers Automated Clearing Services) should have preference.(b) The use of inferencing rules: e.g. two-digit years with a value greater than 50 imply 19xx, those with a value equal to or less than 50 imply 20xx. Rules for century inferencing as a whole must apply to all contexts in which the date is used, although different inferencing rules may apply to different date sets. Where any date elements is represented without a century, the correct century shall be unambiguous for all manipulations involving that element.
(e) Rule 4
A leap year is defined in AS/NZS 3802 as follows: "year, leap: In the Gregorian calendar, a year which has 366 days. A leap year is a year whose number is divisible by four an integral number of times, except that if it is a centennial year it shall be divisible by four hundred an integral number of times". Thus, for example, 2000 is a leap year but 1900 is not.
(ii) General notes
For Rules 1 and 2 in particular, it is recommended that allowable ranges for values of current date and dates to be manipulated be documented, realising that all systems have some limitations on the valid date ranges. The ranges may relate to one or more of the feasible life-span of equipment or products or the span of dates required to be represented by the organisation's business processes. Tests for specifically critical dates may also be added (e.g. for leap years, end of year, etc.). Organisations may wish to append additional material in support of local requirements. Where the term 'century' is used, clear distinction should be made between the 'value' denoting the century (e.g. 20th) and its representation in dates (e.g. 19xx); similarly, 21st and 20xx. In order to encourage a uniform approach to date fields, organisations may wish to consider following the Commonwealth of Australia's convention for expressing the date field- CCYYMMDD
First Published as SAA/SNZ
Second edition, November 1998
|Converted from CHM to HTML with chm2web Standard 2.85 (unicode)|