Date: 9 Oct 1998 23:17:26 -0000 From: "D. J. Bernstein" <djb@cr.yp.to> What is 1 month before 31 March? I see two answers to that question: * ``It's an error to ask that question.'' I.e. the mktime replacement would report an error if asked that question. * 29 February if it's a leap lear, 28 February otherwise. There are reasonable arguments for either answer. Perhaps the standard should leave it open. A closely related question is ``What is 1 minute before 23:59:60?''. Here's a good one: ``What is 1 month before 1 February 1995 in Kiritimati?''. There was no 1 January 1995 in Kiritimati; they skipped a day by moving the clocks ahead 24 hours. Similar issues arise when asking about times that occur within smaller, more typical UTC offset changes. A number of obscure questions arise here, and I'm not sure it's worth standardizing all the answers.