From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Dokos Subject: Re: dates before 1970 Date: Fri, 11 Mar 2011 11:30:15 -0500 Message-ID: <4006.1299861015@alphaville.dokosmarshall.org> References: <87ei6en127.fsf@ucl.ac.uk> <5422.1299798393@alphaville.usa.hp.com> <87ei6ehwld.fsf@ucl.ac.uk> Reply-To: nicholas.dokos@hp.com Return-path: Received: from [140.186.70.92] (port=51988 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Py5EQ-0007sP-5s for emacs-orgmode@gnu.org; Fri, 11 Mar 2011 11:30:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Py5EN-0007zC-TV for emacs-orgmode@gnu.org; Fri, 11 Mar 2011 11:30:25 -0500 Received: from vms173001pub.verizon.net ([206.46.173.1]:46873) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Py5EN-0007yu-QN for emacs-orgmode@gnu.org; Fri, 11 Mar 2011 11:30:23 -0500 Received: from alphaville.dokosmarshall.org ([unknown] [173.76.32.106]) by vms173001.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0LHW00AIHJ6GYZ00@vms173001.mailsrvcs.net> for emacs-orgmode@gnu.org; Fri, 11 Mar 2011 10:30:22 -0600 (CST) In-reply-to: Message from Carsten Dominik of "Fri, 11 Mar 2011 12:36:13 +0100." List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: Carsten Dominik Cc: nicholas.dokos@hp.com, Emacs Org mode mailing list Carsten Dominik wrote: > THis is exactly the point, that it depends on how Emacs was compiled, and what kind of integer is used in the date representation. Signed or unsigend, 32 or 64 bits (I think). > > For example, Bastien can represent dates before 1970. I cannot. > I can represent dates after 2038, Bastien cannot. > > The work-around is to use diary sexps for dates before 1970, that seems to be safe. > And then hope that by 2038, all computers will use 64 bit integers.... > But it's even more than that, no? Emacs's time implementation (current-time, encode/decode etc) would have to change. In fact, this might be the most significant limitation right now: the values they pass around are (hi16 lo16 ms) so they assume that time values are 32 bits, no matter what the underlying implementation says. I use 64-bit Linux on an x86-64 laptop and my time_t is 64 bits (but I don't know if it's signed or unsigned). Time for some experimentation I guess... Nick