<div dir="ltr"><div class="gmail_default" style="font-family:"times new roman",serif">CLDR doesn't formally have offsets. What it has is data like:</div><div class="gmail_default" style="font-family:"times new roman",serif"><br></div><div class="gmail_default" style="font-family:"times new roman",serif">en.xml</div><div class="gmail_default"><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                       </span><metazone type="America_Eastern"></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                             </span><long></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                  </span><generic>Eastern Time</generic></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                   </span><standard>Eastern Standard Time</standard></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                        </span><daylight>Eastern Daylight Time</daylight></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                </span></long></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                         </span><short></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                 </span><generic>ET</generic></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                     </span><standard>EST</standard></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                                  </span><daylight>EDT</daylight></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                          </span></short></div><div class="gmail_default" style="font-family:"times new roman",serif"><span style="white-space:pre">                        </span></metazone></div><div class="gmail_default" style="font-family:"times new roman",serif"><br></div><div class="gmail_default" style="font-family:"times new roman",serif">de.xml</div><div><div><font face="times new roman, serif"><span style="white-space:pre">                        </span><metazone type="America_Eastern"></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                            </span><long></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                                 </span><generic>Nordamerikanische Ostküstenzeit</generic></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                                      </span><standard>Nordamerikanische Ostküsten-Normalzeit</standard></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                                     </span><daylight>Nordamerikanische Ostküsten-Sommerzeit</daylight></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                             </span></long></font></div><div><font face="times new roman, serif"><span style="white-space:pre">                        </span></metazone></font></div></div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif">(Note that abbreviations are only included if they'd be commonly recognized.)</div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif">Each metazones represent a set names that can be used across multiple TZ ids. There can be overrides by TZ id, such as the current:</div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif"><div><span style="white-space:pre">                    </span><zone type="Europe/London"></div><div><span style="white-space:pre">                           </span><long></div><div><span style="white-space:pre">                                  </span><daylight>British Summer Time</daylight></div><div><span style="white-space:pre">                          </span></long></div><div><span style="white-space:pre">                 </span></zone></div><div><span style="white-space:pre">                 </span><zone type="Europe/Dublin"></div><div><span style="white-space:pre">                           </span><long></div><div><span style="white-space:pre">                                  </span><daylight>Irish Standard Time</daylight></div><div><span style="white-space:pre">                          </span></long></div><div><span style="white-space:pre">                 </span></zone></div></div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif">Both of these inherit</div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif"><div><span style="white-space:pre">                    </span><standard>Greenwich Mean Time</standard></div><div><br></div><div>So a current implementation, with no changes, will get for Europe/Dublin:</div><div><br></div><div><standard>Greenwich Mean Time</standard><br></div><div><daylight>Irish Standard Time</daylight><br></div><div><br></div><div><br></div><div>Different clients will use the data in different ways. The source for ICU, for example, reformats to a key-value map:<br></div></div><div style="font-family:"times new roman",serif"><br></div><div style="font-family:"times new roman",serif"><div>        "meta:America_Eastern"{</div><div>            ld{"Eastern Daylight Time"}</div><div>            lg{"Eastern Time"}</div><div>            ls{"Eastern Standard Time"}</div><div>            sd{"EDT"}</div><div>            sg{"ET"}</div><div>            ss{"EST"}</div><div>        }</div><div><br></div><div>The normal interpretation of "standard" and "daylight" keywords or equivalents is that:</div><div><br></div><div>standard_offset = 0</div><div>daylight_offset ≠ 0</div></div></div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font face="'times new roman', serif"><div style="background-color:transparent;margin-top:0px;margin-left:0px;margin-bottom:0px;margin-right:0px"><div></div></div><div style="background-color:transparent;margin-top:0px;margin-left:0px;margin-bottom:0px;margin-right:0px">Mark</div></font><div><div><font face="'times new roman', serif"><i><span style="font-style:normal"><i></i></span><i></i></i></font></div></div></div></div></div></div></div></div></div></div></div></div></div>
<br><div class="gmail_quote">On Wed, Jan 24, 2018 at 10:44 AM, Guy Harris <span dir="ltr"><<a href="mailto:guy@alum.mit.edu" target="_blank">guy@alum.mit.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Jan 23, 2018, at 11:55 AM, Yoshito Umaoka <<a href="mailto:yoshito_umaoka@us.ibm.com">yoshito_umaoka@us.ibm.com</a>> wrote:<br>
<br>
> CLDR does not determine offsets.<br>
<br>
</span>Stephen Colebourne claimed that CLDR determines whether to use the standard or daylight time strings by comparing the "raw offset" (presumably meaning "the offset during standard time") with the "actual offset" (presumably meaning "the offset during daylight savings time").<br>
<br>
Therefore, it *must* know those offsets, otherwise it cannot compare them.<br>
<br>
So let me rephrase the question:<br>
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        How does CLDR obtain those offsets?</blockquote></div><br></div>