<!DOCTYPE html><html lang='en'><head><title>[time.zone.overview]</title><meta charset='UTF-8'/><link rel='stylesheet' type='text/css' href='14882.css'/><link rel='stylesheet' type='text/css' href='expanded.css' title='Notes and examples expanded'/><link rel='alternate stylesheet' type='text/css' href='colored.css' title='Notes and examples colored'/><link rel='alternate stylesheet' type='text/css' href='collapsed.css' title='Notes and examples collapsed'/><link rel='icon' href='icon.png'/></head><body><div class='wrapper'><h1 ><a class='secnum' style='min-width:73pt'>26</a> Time library <a class='abbr_ref' href='./#time'>[time]</a></h1><h2 ><a class='secnum' style='min-width:88pt'>26.10</a> Time zones <a class='abbr_ref' href='time.zone#overview'>[time.zone]</a></h2><h3 ><a class='secnum' style='min-width:103pt'>26.10.5</a> Class <span class='texttt'>time_&shy;zone</span> <a class='abbr_ref' href='time.zone.timezone#time.zone.overview'>[time.zone.timezone]</a></h3><h4 ><a class='secnum' style='min-width:118pt'>26.10.5.1</a> Overview <a class='abbr_ref'>[time.zone.overview]</a></h4><span class='indexparent'><a class='index' id='lib:time_zone'></a></span><pre class='codeblock'>
<span class='keyword'>namespace</span> std<span class='operator'>:</span><span class='operator'>:</span>chrono <span class='curlybracket'>{</span>
  <span class='keyword'>class</span> time_zone <span class='curlybracket'>{</span>
  <span class='keyword'>public</span><span class='operator'>:</span>
    time_zone<span class='parenthesis'>(</span>time_zone<span class='operator'>&amp;</span><span class='operator'>&amp;</span><span class='parenthesis'>)</span> <span class='operator'>=</span> <span class='keyword'>default</span>;
    time_zone<span class='operator'>&amp;</span> <span class='keyword'>operator</span><span class='operator'>=</span><span class='parenthesis'>(</span>time_zone<span class='operator'>&amp;</span><span class='operator'>&amp;</span><span class='parenthesis'>)</span> <span class='operator'>=</span> <span class='keyword'>default</span>;

    <span class='comment'>// unspecified additional constructors</span>

    string_view name<span class='parenthesis'>(</span><span class='parenthesis'>)</span> <span class='keyword'>const</span> <span class='keyword'>noexcept</span>;

    <span class='keyword'>template</span><span class='anglebracket'>&lt;</span><span class='keyword'>class</span> Duration<span class='anglebracket'>&gt;</span> sys_info   get_info<span class='parenthesis'>(</span><span class='keyword'>const</span> sys_time<span class='anglebracket'>&lt;</span>Duration<span class='anglebracket'>&gt;</span><span class='operator'>&amp;</span> st<span class='parenthesis'>)</span>   <span class='keyword'>const</span>;
    <span class='keyword'>template</span><span class='anglebracket'>&lt;</span><span class='keyword'>class</span> Duration<span class='anglebracket'>&gt;</span> local_info get_info<span class='parenthesis'>(</span><span class='keyword'>const</span> local_time<span class='anglebracket'>&lt;</span>Duration<span class='anglebracket'>&gt;</span><span class='operator'>&amp;</span> tp<span class='parenthesis'>)</span> <span class='keyword'>const</span>;

    <span class='keyword'>template</span><span class='anglebracket'>&lt;</span><span class='keyword'>class</span> Duration<span class='anglebracket'>&gt;</span>
      sys_time<span class='anglebracket'>&lt;</span>common_type_t<span class='anglebracket'>&lt;</span>Duration, seconds<span class='anglebracket'>&gt;</span><span class='anglebracket'>&gt;</span>
        to_sys<span class='parenthesis'>(</span><span class='keyword'>const</span> local_time<span class='anglebracket'>&lt;</span>Duration<span class='anglebracket'>&gt;</span><span class='operator'>&amp;</span> tp<span class='parenthesis'>)</span> <span class='keyword'>const</span>;

    <span class='keyword'>template</span><span class='anglebracket'>&lt;</span><span class='keyword'>class</span> Duration<span class='anglebracket'>&gt;</span>
      sys_time<span class='anglebracket'>&lt;</span>common_type_t<span class='anglebracket'>&lt;</span>Duration, seconds<span class='anglebracket'>&gt;</span><span class='anglebracket'>&gt;</span>
        to_sys<span class='parenthesis'>(</span><span class='keyword'>const</span> local_time<span class='anglebracket'>&lt;</span>Duration<span class='anglebracket'>&gt;</span><span class='operator'>&amp;</span> tp, choose z<span class='parenthesis'>)</span> <span class='keyword'>const</span>;

    <span class='keyword'>template</span><span class='anglebracket'>&lt;</span><span class='keyword'>class</span> Duration<span class='anglebracket'>&gt;</span>
      local_time<span class='anglebracket'>&lt;</span>common_type_t<span class='anglebracket'>&lt;</span>Duration, seconds<span class='anglebracket'>&gt;</span><span class='anglebracket'>&gt;</span>
        to_local<span class='parenthesis'>(</span><span class='keyword'>const</span> sys_time<span class='anglebracket'>&lt;</span>Duration<span class='anglebracket'>&gt;</span><span class='operator'>&amp;</span> tp<span class='parenthesis'>)</span> <span class='keyword'>const</span>;
  <span class='curlybracket'>}</span>;
<span class='curlybracket'>}</span>
</pre><div class='para' id='1'><div class='marginalizedparent'><a class='marginalized' href='#1'>1</a></div><div class='sourceLinkParent'><a class='sourceLink' href='https://github.com/Eelis/draft73ca144c7e48612fe72742f9f6a5ec9ad6a934d2/source/time.tex#L9439'>#</a></div><div id='1.sentence-1' class='sentence'>A <span class='texttt'>time_&shy;zone</span> represents all time zone transitions
for a specific geographic area<a class='hidden_link' href='#1.sentence-1'>.</a></div> <div id='1.sentence-2' class='sentence'><span class='texttt'>time_&shy;zone</span> construction is unspecified,
and performed as part of database initialization<a class='hidden_link' href='#1.sentence-2'>.</a></div> <div id='1.note-1' class='note'>[<span style='white-space:nowrap'> </span><a class='note_link' href='#1.note-1'><span class='textit'>Note</span></a><div class='noteBody'><span class='textit'>:</span> <div id='1.sentence-3' class='sentence'><span class='texttt'><span class='keyword'>const</span> time_&shy;zone</span> objects can be accessed
via functions such as <span class='texttt'>locate_&shy;zone</span><a class='hidden_link' href='#1.sentence-3'>.</a></div> —<span style='white-space:nowrap'> </span><i>end note</i></div><span style='white-space:nowrap'> </span>]</div> </div></div></body></html>