Newsgroups: comp.sys.apple2.programmer Path: news.uiowa.edu!chi-news.cic.net!vixen.cso.uiuc.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!dlyons From: dlyons@netcom.com (David A. Lyons) Subject: Re: Year 2000 Message-ID: Organization: Netcom Online Communications Services (408-241-9760 login: guest) References: <4goj9m$ef3@senator-bedfellow.mit.edu> <4gp2qh$ch8@nnrp1.news.primenet.com> Date: Tue, 27 Feb 1996 00:56:33 GMT Lines: 29 Sender: dlyons@netcom11.netcom.com In article <4gp2qh$ch8@nnrp1.news.primenet.com> johnlb@primenet.com (John Bowling) writes: >Besides the program handling the dates correctly, there is a question >about ProDOS and the built in time clock handling the dates correctly also. > >There is a fudge you may be able to use where a value of less than (19)50 is >2000 + the value and greater than (19)50 is 1900 plus the value. This >may or may not work with your program. Please see the ProDOS 8 Technical Note #28: ProDOS Dates--2000 and Beyond, from September 1990, by yours truly. The official story is that a ProDOS year number is 00..99, and that the numbers from 0 to 39 are 2000 to 2039. This matches what the GS clock can be set to. In practice, a lot of 3rd-party software was never updated to follow the technote, and probably mis-behaves in various ways starting in 2000. If you have a very old clock driver that may use year numbers of 100 to 127 (declared illegal by the technote, but never defined clearly before that), it would be good to get a newer driver before 2000. (Similarly, if you're revising your software, you might want to *tolerate* year numbers 100..127. If you're a disk-checking program, you should flag them as errors, and repair them by subtracting 100.) -- Dave Lyons Mr Tangent