Computer bugs in the year 2000

Mike Schloss mike at enmasse.UUCP
Thu Jan 24 09:41:47 AEST 1985


>       I have a friend that raised an interesting question that I immediately
> tried to prove wrong.  He is a programmer and has this notion that when we
> reach the year 2000, computers will not accept the new date.  Will the
> computers assume that it is 1900, or will it even cause a problem?  I
> violently opposed this because it seemed so meaningless.  Computers have
> entered into existence during this century, and has software, specifically
> accounting software, been prepared for this turnover?  If this really
> comes to pass and my friend is correct, what will happen?  Is it anything
> to be concerned about?  I haven't given it much thought, but this programmer
> has.  I thought he was joking but he has even lost sleep over this.  When
> I say 'friend,' I'm NOT referring to myself, if it seemed that way.
> 

I have heard the same rumor from some reliable sources.  When I was working
summers for Prudential a while back I was told the story about this and the
people were serious.  One guy, a serious system programmer, not a hack, told
me he was setting his retirement date according to the date this problem will
manifest itself.  The story goes as follows:

	In IBM's OS/VSI, OS/VSII, and MVS all files have a time stamp
	associated with them, usually the creation date.  If upon creation
	the file is deemed to be temporary the the time stamp becomes the
	expiration date and defaults to sometime in the future.  The
	difference between a creation date and expiration date is the
	expiration date has the high order bit set. [See the problem coming]
	The problem is that sometime in 2000 (I dont think its midnight
	Jan 1) the most significant bit in the timestamp will change
	and the system will then think that all files on all disk drives
	are temporary and should have been deleted a long time ago.
	Net result ... All files get deleted.



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