From owner-freebsd-questions@FreeBSD.ORG Tue Apr 22 12:24:59 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7771137B401 for ; Tue, 22 Apr 2003 12:24:59 -0700 (PDT) Received: from smtpout.mac.com (A17-250-248-89.apple.com [17.250.248.89]) by mx1.FreeBSD.org (Postfix) with ESMTP id EC4AF43F85 for ; Tue, 22 Apr 2003 12:24:58 -0700 (PDT) (envelope-from cswiger@mac.com) Received: from asmtp02.mac.com (asmtp02-qfe3 [10.13.10.66]) by smtpout.mac.com (Xserve/MantshX 2.0) with ESMTP id h3MJOwjC020012 for ; Tue, 22 Apr 2003 12:24:58 -0700 (PDT) Received: from mac.com ([68.161.244.25]) by asmtp02.mac.com (Netscape Messaging Server 4.15) with ESMTP id HDRF9M00.J42 for ; Tue, 22 Apr 2003 12:24:58 -0700 Date: Tue, 22 Apr 2003 15:26:19 -0400 Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v552) From: Charles Swiger To: FreeBSD-Questions@freebsd.org Content-Transfer-Encoding: 7bit In-Reply-To: <20030422184554.GA13432@grumpy.dyndns.org> Message-Id: <4B518202-74F8-11D7-BCB7-003065ABFD92@mac.com> X-Mailer: Apple Mail (2.552) Subject: Re: Accurate time without a network connection? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Apr 2003 19:24:59 -0000 On Tuesday, April 22, 2003, at 02:45 PM, David Kelly wrote: > Looking for options to keep system time moderately accurate at a site > without network access. So the normal application of ntpd over IP is > not viable. Dialup modem not allowed either. > > Definition of "moderately accurate": doesn't have to be any better than > I can set my watch, travel to the site, and set the system time. It > just > has to eliminate "travel to the site." Ok. If you run NTPD with only the local hardware clock for a reference, wait for a week, and then see how the intrinsic drift of the hardware compares with "real time" (using your watch or some other time source), you can adjust /etc/ntp.drift by hand. This isn't going to be perfect, but it's going to be much more accurate than doing nothing. -- -Chuck