<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="Generator" content="Microsoft Exchange Server">
<!-- converted from rtf -->
<style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --></style>
</head>
<body>
<font face="Calibri, sans-serif" size="2">
<div>Hi:</div>
<div> </div>
<div>There is an international standard for representation of dates and times:<b> ISO 8601 </b>(see <a href="http://dotat.at/tmp/ISO_8601-2004_E.pdf"><font color="#0000FF"><u>http://dotat.at/tmp/ISO_8601-2004_E.pdf</u></font></a>).</div>
<div> </div>
<div>According to ISO 8601, “<i>the representation</i><i> of the difference (between local time and UTC) can be expressed in hours and minutes, or hours only. It shall be expressed as </i><i><b>positive</b></i><i> (i.e. with the leading </i><i><b>plus sign</b></i><i>
[</i><i>+</i><i>]) if the local time is </i><i><b>ahead</b></i><i> of or equal to UTC… and as</i><i><b> negative </b></i><i>(i.e. with the leading </i><i><b>minus sign</b></i><i> [-]) if it is </i><i><b>behind</b></i><i> UTC</i>.”</div>
<div> </div>
<div>And, also according to ISO 86001, <b>ahead</b> of UTC means <u><b>east of Greenwich</b></u> and <b>behind</b> UTC means <u><b>west of Greenwich</b></u>. For instance, standard offset for Geneva, Switzerland (one hour ahead of UTC) is +01 or +01:00 and
standard offset for New York, USA (five hours behind UTC) is -05:00 or -05.</div>
<div> </div>
<div>I know, according with this standard, all time zones names in America would be “negative”… but blame it on the <b>International Organization for Standardization</b>.</div>
<div> </div>
<div>Best regards.</div>
<div><font face="Consolas, monospace" size="2">--</font></div>
<div><font face="Consolas, monospace" size="2">Rodrigo Díaz López</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">-----Mensaje original-----<br>
De: Alain Petit [<a href="mailto:alain.petit@oracle.com">mailto:alain.petit@oracle.com</a>]
<br>
Enviado el: jueves, 03 de febrero de 2011 21:03<br>
Para: tz@elsie.nci.nih.gov; tz@lecserver.nci.nih.gov<br>
CC: EXIS.Diaz Lopez, Rodrigo<br>
Asunto: RE: FW: "Etc\GMT" positive and negative</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">Hi</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">I found the following in the 'etcetera' file.</font></div>
<div><font face="Consolas, monospace" size="2">This seems to explain why your 'positive' zone translate to a 'negative' offset.</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2"># We use POSIX-style signs in the Zone names and the output abbreviations,</font></div>
<div><font face="Consolas, monospace" size="2"># even though this is the opposite of what many people expect.</font></div>
<div><font face="Consolas, monospace" size="2"># POSIX has positive signs west of Greenwich, but many people expect</font></div>
<div><font face="Consolas, monospace" size="2"># positive signs east of Greenwich. For example, TZ='Etc/GMT+4' uses</font></div>
<div><font face="Consolas, monospace" size="2"># the abbreviation "GMT+4" and corresponds to 4 hours behind UTC</font></div>
<div><font face="Consolas, monospace" size="2"># (i.e. west of Greenwich) even though many people would expect it to</font></div>
<div><font face="Consolas, monospace" size="2"># mean 4 hours ahead of UTC (i.e. east of Greenwich). </font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">-Alain</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">-----Original Message-----</font></div>
<div><font face="Consolas, monospace" size="2">From: Ian Abbott [<a href="mailto:abbotti@mev.co.uk">mailto:abbotti@mev.co.uk</a>] </font></div>
<div><font face="Consolas, monospace" size="2">Sent: Wednesday, February 02, 2011 7:42 PM</font></div>
<div><font face="Consolas, monospace" size="2">To: tz@lecserver.nci.nih.gov</font></div>
<div><font face="Consolas, monospace" size="2">Cc: exis.rdiaz@iberia.es</font></div>
<div><font face="Consolas, monospace" size="2">Subject: Re: FW: "Etc\GMT" positive and negative</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">> From: EXIS.Diaz Lopez, Rodrigo [<a href="mailto:EXIS.rdiaz@iberia.es">mailto:EXIS.rdiaz@iberia.es</a>] Sent:</font></div>
<div><font face="Consolas, monospace" size="2">> Tuesday, February 01, 2011 12:25 To: tz@elsie.nci.nih.gov Subject:</font></div>
<div><font face="Consolas, monospace" size="2">> "Etc\GMT" positive and negative</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> Hi:</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> I think I found a bug with the "Etc\GMT" zones.</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> If you use a "positive zone" like Etc\GMT+2 for calculate actual</font></div>
<div><font face="Consolas, monospace" size="2">> local time in this zone you obtain. local time for Etc\GMT-2 (¡a</font></div>
<div><font face="Consolas, monospace" size="2">> negative zone!). For instance, its' 5:00 PM (UTC/GMT), so in GMT+2</font></div>
<div><font face="Consolas, monospace" size="2">> zone (Greece) the local time must be 7:00 PM. But, if you use TZ</font></div>
<div><font face="Consolas, monospace" size="2">> Database, you obtain. ¡3:00 PM!</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> And the opposite for "negative zones".</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> Is a bit funny. Please, check it.</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> I found a web page</font></div>
<div><font face="Consolas, monospace" size="2">> (<a href="http://www.gsp.com/support/virtual/admin/unix/tz/gmt/">http://www.gsp.com/support/virtual/admin/unix/tz/gmt/</a>) that use tz</font></div>
<div><font face="Consolas, monospace" size="2">> database (I think) and shows this error.</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> Best regards.</font></div>
<div><font face="Consolas, monospace" size="2">></font></div>
<div><font face="Consolas, monospace" size="2">> P.S.: It is possible that the problem was with the "codes", because</font></div>
<div><font face="Consolas, monospace" size="2">> in the world there are "GMT+13" and "GMT+14" zones, and these zones</font></div>
<div><font face="Consolas, monospace" size="2">> do not exist in tz database. However, in tz database exists "GMT-13"</font></div>
<div><font face="Consolas, monospace" size="2">> and "GMT-14" zones, that not exist in the real world.</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">Perhaps this is related to the historical "America not wanting to be</font></div>
<div><font face="Consolas, monospace" size="2">negative" problem that gives us "EST5" being the same as "-0500" in</font></div>
<div><font face="Consolas, monospace" size="2">RFC822 terms?</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2">-- </font></div>
<div><font face="Consolas, monospace" size="2">-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@mev.co.uk> )=-</font></div>
<div><font face="Consolas, monospace" size="2">-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-</font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Consolas, monospace" size="2"> </font></div>
<div><font face="Times New Roman, serif" size="3"> </font></div>
<div><font face="Times New Roman, serif" size="2">IBERIA.com</font></div>
<div><font face="Times New Roman, serif" size="2">Tu viaje de principio a fin</font></div>
<div><font face="Times New Roman, serif" size="2"> </font></div>
<div><font face="Times New Roman, serif" size="2">IBERIA.com</font></div>
<div><font face="Times New Roman, serif" size="2">Your journey from start to finish </font></div>
</font>
</body>
</html>