Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1negAC-0004Cq-VP for pgsql-hackers@arkaria.postgresql.org; Wed, 13 Apr 2022 16:48:17 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1negAB-0000qP-FG for pgsql-hackers@arkaria.postgresql.org; Wed, 13 Apr 2022 16:48:15 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1negAA-0000qF-QM for pgsql-hackers@lists.postgresql.org; Wed, 13 Apr 2022 16:48:15 +0000 Received: from anastigmatix.net ([68.171.219.55]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1negA8-0001lq-DS for pgsql-hackers@lists.postgresql.org; Wed, 13 Apr 2022 16:48:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=anastigmatix.net; s=default; h=Content-Transfer-Encoding:Content-Type: Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date:MIME-Version:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9awack5Mhb3ePNU3HNn8RXsR/2D46Pb/yjNzZ9iUHDE=; b=PhW3rn+J17i7o+avZh6r8vlUvv NAERUpypJRz9TVe+y+WOSbjpxDQ1n3XyIxUJ2OacYVkDwMVGOmh2YzE/PA1lWDekRzoI6I0foqdpw MZaivoAfuV6y4hgpAGp5+5LPPEYOSuS/1kIc72aaJApqz3IEHq5FTN+CoVYpDciN3uCr8s3mXoT4U qrzpciVnANwermmzQLTp0Ol7G6QetdFPwx+WHugDRYcS7YK2TvffwC0os87PY/1Y/Cfw12kSc77+N nwN3RSDDPz4WKCo7MDbLYmW8boPMMlMSlD2rv5dm01dH+hTxCUadPlWnGqpt5s+4ppJ74IKAppRIg Bjle3iDQ==; Received: from [::1] (port=54030 helo=bay.acenet.us) by bay.acenet.us with esmtpa (Exim 4.95) (envelope-from ) id 1negA6-008HiM-Re; Wed, 13 Apr 2022 12:48:11 -0400 MIME-Version: 1.0 Date: Wed, 13 Apr 2022 12:48:10 -0400 From: chap@anastigmatix.net To: Dave Cramer Cc: PostgreSQL Hackers Subject: Re: timezones BCE In-Reply-To: References: User-Agent: Roundcube Webmail/1.4.12 Message-ID: <17e2658c31d8284355de0d3230445855@anastigmatix.net> X-Sender: chap@anastigmatix.net Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bay.acenet.us X-AntiAbuse: Original Domain - lists.postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - anastigmatix.net X-Get-Message-Sender-Via: bay.acenet.us: authenticated_id: chap@anastigmatix.net X-Authenticated-Sender: bay.acenet.us: chap@anastigmatix.net X-Source: X-Source-Args: X-Source-Dir: X-From-Rewrite: unmodified, already matched List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On 2022-04-13 12:33, Dave Cramer wrote: > test=# set timezone to 'America/Toronto'; > SET > test=# select '0101-01-01'::timestamptz; > timestamptz > ------------------------------ > 0101-01-01 00:00:00-05:17:32 > > Specifically why the -05:17:32 Timezones were regularized into their (typically hour-wide) chunks during a period around the late nineteenth century IIRC. If you decompile the zoneinfo database to look at America/Toronto, you will probably find an entry for dates earlier than when the regularized zones were established there, and that entry will have an offset reflecting Toronto's actual longitude. Regards, -Chap