MVS North System
Tape Management SystemCoded Dates and the Year 2000
Have you have been worrying what would happen when coded expiration dates in the tape management system (TMS) became real dates? This article should put you at ease. We are talking about coded dates 98000, 99000 and 99365. There is no conflict with dates 98000 (used for foreign tapes) and 99000 (used to keep tapes until they are uncataloged)they are not valid Julian dates (since there is no day "0" in a year).
How to Avoid Problems with 99365
In the case of the coded date 99365, Computer Associates has adopted a solution that in essence, says, "Coded dates are still coded dates and will keep their meaning. If you want them to mean actual dates you will have to take an additional step."
To have the Julian date 99365 really mean the last day of the year 1999, you must include an additional DD card in the step JCL that looks like:
//TMNOKEY DD DUMMY
If this DD statement in not present in the step JCL, then EXPDT=99365 still means keep the tape permanently.
A Simple Solution
Rather than go to the trouble of including an extra DD card to get the real date 99365, you might find it much easier to settle for 99364 or 00001. The date 00001, by the way, is the Julian date for January 1, 2000.
Any tape given permanent or catalog status in the past is safe. The coded dates are actually stored in the TMS records in a way that cannot be misinterpreted.
TMS itself has been ready for the year 2000 since version 5.0 was released over two years ago. CIT staff members have been working on the in-house software that has grown up around TMS and that software, too, will be ready for the year 2000 by the end of 1998.
Interface 208 - December 15, 1998