On Sun, 27 Sep 2009 05:32:31 -0500, William H. Blair wrote: > >There was some question which representation would be >best to represent dates>1999: yyyydddF or 0cyydddF. The >several IBMers with whom folks like us at GUIDE on some >of the futures task forces discussed the issue eventually >decided that 0cyydddF was the best approach because code >to interpret the century nybble or byte could be put into >place sooner rather than later, and would work correctly >with operating systems that did not yet return 0cyy or >ccyy (whereas if MVS started returning 19yy, then lots >of code was going to break). It was ugly, but it kept >old code running and new code working on old operating >systems. And so forth. Thus, the new algorithm for date >exhibition would be: Year = 1900 + (100*c) + yy (where >ddd, of course, remained interpreted as it always had >been). > After the fact: At that time there must have been long-term contracts originating in the 1800's, and a significant number of persons living with birth dates in the 1800's. So I wonder why the scheme chosen was not the last 4 digits of yyyy+8900. It would have matched the chosen scheme for the 20th and 21st centuries, and provided for smooth extension to the 19th and earlier.
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