Communicator 3000 MPE/iX Release 6.0 (Platform Software Release C.60.00) (30216-90269)

Chapter 9 119

Year 2000 Enhancements

Year 2000 Enhancements for MPE/iX

by M Gopalakrishnan

Commercial System Division

Overview

This version of MPE/iX provides enhancements to the operating system

for the year 2000 and beyond. The enhancements include the

enhancements to the operating system commands, utilities, VPLUS

and databases. This article explains the enhancements.

Background

The year 2000 issues stem from the ability to handle correctly the year

2000 and beyond. This is particularly an issue for systems and

applications that are using a two-digit year to express dates. There are

a few commands, utilities, and databases in MPE/iX which were

designed to handle two-digit years and these had to be enhanced to

support year 2000 and beyond.

The year 2000 is a leap year, and this also had to be addressed. The

MPE/iX operating system uses the Gregorian calendar and its

deﬁnition of leap year: any year that is exactly divisible by 400, or that

is exactly divisible by 4 and not exactly divisible by 100.

Two-Digit Years Interpretation

One of the ways for handling two-digit year input is to interpret the

years in the method called ﬁxed window method. In this method, the

two-digit years map as follows:

• 00 .. 49 maps to 2000 .. 2049

• 50 .. 99 maps to 1950 .. 1999

For example, both of the following STREAM commands will schedule the

JOBFILE as January 21, 2001:

:STREAM JOBFILE;DATE=01/21/2001

:STREAM JOBFILE;DATE=01/21/01

Intrinsics

The CALENDAR intrinsic and CALENDAR date representation format are

widely used in MPE/iX. There are many other intrinsics that accept or

return dates in calendar format. The following discussion clariﬁes the

interpretation of calendar format year value.