hasufell/pnmixer-rust
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
d31eddae16
pnmixer-rust/chrono/index.html

487 lines
44 KiB
HTML
Raw Normal View History

Update and fix
2017-07-14 23:30:16 +00:00
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="rustdoc">
<meta name="description" content="API documentation for the Rust `chrono` crate.">
<meta name="keywords" content="rust, rustlang, rust-lang, chrono">
<title>chrono - Rust</title>
<link rel="stylesheet" type="text/css" href="../normalize.css">
<link rel="stylesheet" type="text/css" href="../rustdoc.css">
<link rel="stylesheet" type="text/css" href="../main.css">
</head>
<body class="rustdoc mod">
<!--[if lte IE 8]>
<div class="warning">
This old browser is unsupported and will most likely display funky
things.
</div>
<![endif]-->
<nav class="sidebar">
<p class='location'>Crate chrono</p><div class="block items"><ul><li><a href="#reexports">Reexports</a></li><li><a href="#modules">Modules</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#traits">Traits</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'chrono', ty: 'mod', relpath: '../'};</script>
</nav>
<nav class="sub">
<form class="search-form js-only">
<div class="search-container">
<input class="search-input" name="search"
autocomplete="off"
placeholder="Click or press ‘S’ to search, ‘?’ for more options…"
type="search">
</div>
</form>
</nav>
<section id='main' class="content">
<h1 class='fqn'><span class='in-band'>Crate <a class="mod" href=''>chrono</a></span><span class='out-of-band'><span id='render-detail'>
<a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">
[<span class='inner'>&#x2212;</span>]
</a>
</span><a class='srclink' href='../src/chrono/lib.rs.html#5-732' title='goto source code'>[src]</a></span></h1>
<div class='docblock'>
<h1 id='chrono-0225' class='section-header'><a href='#chrono-0225'>Chrono 0.2.25</a></h1>
<p>Date and time handling for Rust. (also known as <code>rust-chrono</code>)
It aims to be a feature-complete superset of
the <a href="https://github.com/rust-lang-deprecated/time">time</a> library.
In particular,</p>
<ul>
<li>Chrono strictly adheres to ISO 8601.</li>
<li>Chrono is timezone-aware by default, with separate timezone-naive types.</li>
<li>Chrono is space-optimal and (while not being the primary goal) reasonably efficient.</li>
</ul>
<p>There were several previous attempts to bring a good date and time library to Rust,
which Chrono builts upon and should acknowledge:</p>
<ul>
<li><a href="https://github.com/rust-lang/rust-wiki-backup/blob/master/Lib-datetime.md">Initial research on
the wiki</a></li>
<li>Dietrich Epp&#39;s <a href="https://github.com/depp/datetime-rs">datetime-rs</a></li>
<li>Luis de Bethencourt&#39;s <a href="https://github.com/luisbg/rust-datetime">rust-datetime</a></li>
</ul>
<h2 id='usage' class='section-header'><a href='#usage'>Usage</a></h2>
<p>Put this in your <code>Cargo.toml</code>:</p>
<pre><code class="language-toml">[dependencies]
chrono = &quot;0.2&quot;
</code></pre>
<p>Or, if you want <a href="https://github.com/serde-rs/serde">Serde</a> or
<a href="https://github.com/rust-lang-nursery/rustc-serialize">rustc-serialize</a> support,
include the features like this:</p>
<pre><code class="language-toml">[dependencies]
chrono = { version = &quot;0.2&quot;, features = [&quot;serde&quot;, &quot;rustc-serialize&quot;] }
</code></pre>
<p>Then put this in your crate root:</p>
<pre class="rust rust-example-rendered">
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">chrono</span>;</pre>
<h2 id='overview' class='section-header'><a href='#overview'>Overview</a></h2>
<h3 id='duration' class='section-header'><a href='#duration'>Duration</a></h3>
<p><a href="./struct.Duration.html"><strong><code>Duration</code></strong></a>
represents the magnitude of a time span. <code>Duration</code> used to be provided by Chrono.
It has been moved to the <code>time</code> crate as the
<a href="https://doc.rust-lang.org/time/time/struct.Duration.html"><code>time::Duration</code></a> type, but is
still re-exported from Chrono.</p>
<h3 id='date-and-time' class='section-header'><a href='#date-and-time'>Date and Time</a></h3>
<p>Chrono provides a
<a href="./datetime/struct.DateTime.html"><strong><code>DateTime</code></strong></a>
type to represent a date and a time in a timezone.</p>
<p>For more abstract moment-in-time tracking such as internal timekeeping
that is unconcerned with timezones, consider
<a href="https://doc.rust-lang.org/std/time/struct.SystemTime.html"><code>time::SystemTime</code></a>,
which tracks your system clock, or
<a href="https://doc.rust-lang.org/std/time/struct.Instant.html"><code>time::Instant</code></a>, which
is an opaque but monotonically-increasing representation of a moment in time.</p>
<p><code>DateTime</code> is timezone-aware and must be constructed from
the <a href="./offset/trait.TimeZone.html"><strong><code>TimeZone</code></strong></a> object,
which defines how the local date is converted to and back from the UTC date.
There are three well-known <code>TimeZone</code> implementations:</p>
<ul>
<li><p><a href="./offset/utc/struct.UTC.html"><strong><code>UTC</code></strong></a> specifies the UTC time zone. It is most efficient.</p></li>
<li><p><a href="./offset/local/struct.Local.html"><strong><code>Local</code></strong></a> specifies the system local time zone.</p></li>
<li><p><a href="./offset/fixed/struct.FixedOffset.html"><strong><code>FixedOffset</code></strong></a> specifies
an arbitrary, fixed time zone such as UTC+09:00 or UTC-10:30.
This often results from the parsed textual date and time.
Since it stores the most information and does not depend on the system environment,
you would want to normalize other <code>TimeZone</code>s into this type.</p></li>
</ul>
<p><code>DateTime</code>s with different <code>TimeZone</code> types are distinct and do not mix,
but can be converted to each other using
the <a href="./datetime/struct.DateTime.html#method.with_timezone"><code>DateTime::with_timezone</code></a> method.</p>
<p>You can get the current date and time in the UTC time zone
(<a href="./offset/utc/struct.UTC.html#method.now"><code>UTC::now()</code></a>)
or in the local time zone
(<a href="./offset/local/struct.Local.html#method.now"><code>Local::now()</code></a>).</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="kw">let</span> <span class="ident">utc</span>: <span class="ident">DateTime</span><span class="op">&lt;</span><span class="ident">UTC</span><span class="op">&gt;</span> <span class="op">=</span> <span class="ident">UTC</span>::<span class="ident">now</span>(); <span class="comment">// e.g. `2014-11-28T12:45:59.324310806Z`</span>
<span class="kw">let</span> <span class="ident">local</span>: <span class="ident">DateTime</span><span class="op">&lt;</span><span class="ident">Local</span><span class="op">&gt;</span> <span class="op">=</span> <span class="ident">Local</span>::<span class="ident">now</span>(); <span class="comment">// e.g. `2014-11-28T21:45:59.324310806+09:00`</span></pre>
<p>Alternatively, you can create your own date and time.
This is a bit verbose due to Rust&#39;s lack of function and method overloading,
but in turn we get a rich combination of initialization methods.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="kw">let</span> <span class="ident">dt</span> <span class="op">=</span> <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>); <span class="comment">// `2014-07-08T09:10:11Z`</span>
<span class="comment">// July 8 is 188th day of the year 2014 (`o` for &quot;ordinal&quot;)</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>, <span class="ident">UTC</span>.<span class="ident">yo</span>(<span class="number">2014</span>, <span class="number">189</span>).<span class="ident">and_hms</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>));
<span class="comment">// July 8 is Tuesday in ISO week 28 of the year 2014.</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>, <span class="ident">UTC</span>.<span class="ident">isoywd</span>(<span class="number">2014</span>, <span class="number">28</span>, <span class="ident">Weekday</span>::<span class="ident">Tue</span>).<span class="ident">and_hms</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>));
<span class="kw">let</span> <span class="ident">dt</span> <span class="op">=</span> <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_milli</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12</span>); <span class="comment">// `2014-07-08T09:10:11.012Z`</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>, <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_micro</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12_000</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>, <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_nano</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12_000_000</span>));
<span class="comment">// dynamic verification</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd_opt</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_opt</span>(<span class="number">21</span>, <span class="number">15</span>, <span class="number">33</span>),
<span class="ident">LocalResult</span>::<span class="ident">Single</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms</span>(<span class="number">21</span>, <span class="number">15</span>, <span class="number">33</span>)));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd_opt</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_opt</span>(<span class="number">80</span>, <span class="number">15</span>, <span class="number">33</span>), <span class="ident">LocalResult</span>::<span class="prelude-val">None</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd_opt</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">38</span>).<span class="ident">and_hms_opt</span>(<span class="number">21</span>, <span class="number">15</span>, <span class="number">33</span>), <span class="ident">LocalResult</span>::<span class="prelude-val">None</span>);
<span class="comment">// other time zone objects can be used to construct a local datetime.</span>
<span class="comment">// obviously, `local_dt` is normally different from `dt`, but `fixed_dt` should be identical.</span>
<span class="kw">let</span> <span class="ident">local_dt</span> <span class="op">=</span> <span class="ident">Local</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_milli</span>(<span class="number">9</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12</span>);
<span class="kw">let</span> <span class="ident">fixed_dt</span> <span class="op">=</span> <span class="ident">FixedOffset</span>::<span class="ident">east</span>(<span class="number">9</span> <span class="op">*</span> <span class="number">3600</span>).<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">7</span>, <span class="number">8</span>).<span class="ident">and_hms_milli</span>(<span class="number">18</span>, <span class="number">10</span>, <span class="number">11</span>, <span class="number">12</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>, <span class="ident">fixed_dt</span>);</pre>
<p>Various properties are available to the date and time, and can be altered individually.
Most of them are defined in the traits <a href="./trait.Datelike.html"><code>Datelike</code></a> and
<a href="./trait.Timelike.html"><code>Timelike</code></a> which you should <code>use</code> before.
Addition and subtraction is also supported.
The following illustrates most supported operations to the date and time:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="comment">// assume this returned `2014-11-28T21:45:59.324310806+09:00`:</span>
<span class="kw">let</span> <span class="ident">dt</span> <span class="op">=</span> <span class="ident">Local</span>::<span class="ident">now</span>();
<span class="comment">// property accessors</span>
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">dt</span>.<span class="ident">year</span>(), <span class="ident">dt</span>.<span class="ident">month</span>(), <span class="ident">dt</span>.<span class="ident">day</span>()), (<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">dt</span>.<span class="ident">month0</span>(), <span class="ident">dt</span>.<span class="ident">day0</span>()), (<span class="number">10</span>, <span class="number">27</span>)); <span class="comment">// for unfortunate souls</span>
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">dt</span>.<span class="ident">hour</span>(), <span class="ident">dt</span>.<span class="ident">minute</span>(), <span class="ident">dt</span>.<span class="ident">second</span>()), (<span class="number">21</span>, <span class="number">45</span>, <span class="number">59</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">weekday</span>(), <span class="ident">Weekday</span>::<span class="ident">Fri</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">weekday</span>().<span class="ident">number_from_monday</span>(), <span class="number">5</span>); <span class="comment">// Mon=1, ..., Sat=7</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">ordinal</span>(), <span class="number">332</span>); <span class="comment">// the day of year</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">num_days_from_ce</span>(), <span class="number">735565</span>); <span class="comment">// the number of days from and including Jan 1, 1</span>
<span class="comment">// time zone accessor and manipulation</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">offset</span>().<span class="ident">local_minus_utc</span>(), <span class="ident">Duration</span>::<span class="ident">hours</span>(<span class="number">9</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">timezone</span>(), <span class="ident">FixedOffset</span>::<span class="ident">east</span>(<span class="number">9</span> <span class="op">*</span> <span class="number">3600</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">with_timezone</span>(<span class="kw-2">&amp;</span><span class="ident">UTC</span>), <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>).<span class="ident">and_hms_nano</span>(<span class="number">12</span>, <span class="number">45</span>, <span class="number">59</span>, <span class="number">324310806</span>));
<span class="comment">// a sample of property manipulations (validates dynamically)</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">with_day</span>(<span class="number">29</span>).<span class="ident">unwrap</span>().<span class="ident">weekday</span>(), <span class="ident">Weekday</span>::<span class="ident">Sat</span>); <span class="comment">// 2014-11-29 is Saturday</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">with_day</span>(<span class="number">32</span>), <span class="prelude-val">None</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">with_year</span>(<span class="op">-</span><span class="number">300</span>).<span class="ident">unwrap</span>().<span class="ident">num_days_from_ce</span>(), <span class="op">-</span><span class="number">109606</span>); <span class="comment">// November 29, 301 BCE</span>
<span class="comment">// arithmetic operations</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">14</span>).<span class="ident">and_hms</span>(<span class="number">8</span>, <span class="number">9</span>, <span class="number">10</span>) <span class="op">-</span> <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">14</span>).<span class="ident">and_hms</span>(<span class="number">10</span>, <span class="number">9</span>, <span class="number">8</span>),
<span class="ident">Duration</span>::<span class="ident">seconds</span>(<span class="op">-</span><span class="number">2</span> <span class="op">*</span> <span class="number">3600</span> <span class="op">+</span> <span class="number">2</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">1970</span>, <span class="number">1</span>, <span class="number">1</span>).<span class="ident">and_hms</span>(<span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>) <span class="op">+</span> <span class="ident">Duration</span>::<span class="ident">seconds</span>(<span class="number">1_000_000_000</span>),
<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2001</span>, <span class="number">9</span>, <span class="number">9</span>).<span class="ident">and_hms</span>(<span class="number">1</span>, <span class="number">46</span>, <span class="number">40</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">1970</span>, <span class="number">1</span>, <span class="number">1</span>).<span class="ident">and_hms</span>(<span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>) <span class="op">-</span> <span class="ident">Duration</span>::<span class="ident">seconds</span>(<span class="number">1_000_000_000</span>),
<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">1938</span>, <span class="number">4</span>, <span class="number">24</span>).<span class="ident">and_hms</span>(<span class="number">22</span>, <span class="number">13</span>, <span class="number">20</span>));</pre>
<p>Formatting is done via the <a href="./datetime/struct.DateTime.html#method.format"><code>format</code></a> method,
which format is equivalent to the familiar <code>strftime</code> format.
(See the <a href="./format/strftime/index.html#specifiers"><code>format::strftime</code> module documentation</a>
for full syntax.)</p>
<p>The default <code>to_string</code> method and <code>{:?}</code> specifier also give a reasonable representation.
Chrono also provides <a href="./datetime/struct.DateTime.html#method.to_rfc2822"><code>to_rfc2822</code></a> and
<a href="./datetime/struct.DateTime.html#method.to_rfc3339"><code>to_rfc3339</code></a> methods
for well-known formats.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="kw">let</span> <span class="ident">dt</span> <span class="op">=</span> <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>).<span class="ident">and_hms</span>(<span class="number">12</span>, <span class="number">0</span>, <span class="number">9</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">format</span>(<span class="string">&quot;%Y-%m-%d %H:%M:%S&quot;</span>).<span class="ident">to_string</span>(), <span class="string">&quot;2014-11-28 12:00:09&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">format</span>(<span class="string">&quot;%a %b %e %T %Y&quot;</span>).<span class="ident">to_string</span>(), <span class="string">&quot;Fri Nov 28 12:00:09 2014&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">format</span>(<span class="string">&quot;%a %b %e %T %Y&quot;</span>).<span class="ident">to_string</span>(), <span class="ident">dt</span>.<span class="ident">format</span>(<span class="string">&quot;%c&quot;</span>).<span class="ident">to_string</span>());
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">to_string</span>(), <span class="string">&quot;2014-11-28 12:00:09 UTC&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">to_rfc2822</span>(), <span class="string">&quot;Fri, 28 Nov 2014 12:00:09 +0000&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">dt</span>.<span class="ident">to_rfc3339</span>(), <span class="string">&quot;2014-11-28T12:00:09+00:00&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">&quot;{:?}&quot;</span>, <span class="ident">dt</span>), <span class="string">&quot;2014-11-28T12:00:09Z&quot;</span>);</pre>
<p>Parsing can be done with three methods:</p>
<ol>
<li><p>The standard <a href="https://doc.rust-lang.org/std/str/trait.FromStr.html"><code>FromStr</code></a> trait
(and <a href="https://doc.rust-lang.org/std/primitive.str.html#method.parse"><code>parse</code></a> method
on a string) can be used for parsing <code>DateTime&lt;FixedOffset&gt;</code>, <code>DateTime&lt;UTC&gt;</code> and
<code>DateTime&lt;Local&gt;</code> values. This parses what the <code>{:?}</code>
(<a href="https://doc.rust-lang.org/std/fmt/trait.Debug.html"><code>std::fmt::Debug</code></a>)
format specifier prints, and requires the offset to be present.</p></li>
<li><p><a href="./datetime/struct.DateTime.html#method.parse_from_str"><code>DateTime::parse_from_str</code></a> parses
a date and time with offsets and returns <code>DateTime&lt;FixedOffset&gt;</code>.
This should be used when the offset is a part of input and the caller cannot guess that.
It <em>cannot</em> be used when the offset can be missing.
<a href="./datetime/struct.DateTime.html#method.parse_from_rfc2822"><code>DateTime::parse_from_rfc2822</code></a>
and
<a href="./datetime/struct.DateTime.html#method.parse_from_rfc3339"><code>DateTime::parse_from_rfc3339</code></a>
are similar but for well-known formats.</p></li>
<li><p><a href="./offset/trait.TimeZone.html#method.datetime_from_str"><code>Offset::datetime_from_str</code></a> is
similar but returns <code>DateTime</code> of given offset.
When the explicit offset is missing from the input, it simply uses given offset.
It issues an error when the input contains an explicit offset different
from the current offset.</p></li>
</ol>
<p>More detailed control over the parsing process is available via
<a href="./format/index.html"><code>format</code></a> module.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="kw">let</span> <span class="ident">dt</span> <span class="op">=</span> <span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>).<span class="ident">and_hms</span>(<span class="number">12</span>, <span class="number">0</span>, <span class="number">9</span>);
<span class="kw">let</span> <span class="ident">fixed_dt</span> <span class="op">=</span> <span class="ident">dt</span>.<span class="ident">with_timezone</span>(<span class="kw-2">&amp;</span><span class="ident">FixedOffset</span>::<span class="ident">east</span>(<span class="number">9</span><span class="kw-2">*</span><span class="number">3600</span>));
<span class="comment">// method 1</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="string">&quot;2014-11-28T12:00:09Z&quot;</span>.<span class="ident">parse</span>::<span class="op">&lt;</span><span class="ident">DateTime</span><span class="op">&lt;</span><span class="ident">UTC</span><span class="op">&gt;&gt;</span>(), <span class="prelude-val">Ok</span>(<span class="ident">dt</span>.<span class="ident">clone</span>()));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="string">&quot;2014-11-28T21:00:09+09:00&quot;</span>.<span class="ident">parse</span>::<span class="op">&lt;</span><span class="ident">DateTime</span><span class="op">&lt;</span><span class="ident">UTC</span><span class="op">&gt;&gt;</span>(), <span class="prelude-val">Ok</span>(<span class="ident">dt</span>.<span class="ident">clone</span>()));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="string">&quot;2014-11-28T21:00:09+09:00&quot;</span>.<span class="ident">parse</span>::<span class="op">&lt;</span><span class="ident">DateTime</span><span class="op">&lt;</span><span class="ident">FixedOffset</span><span class="op">&gt;&gt;</span>(), <span class="prelude-val">Ok</span>(<span class="ident">fixed_dt</span>.<span class="ident">clone</span>()));
<span class="comment">// method 2</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">DateTime</span>::<span class="ident">parse_from_str</span>(<span class="string">&quot;2014-11-28 21:00:09 +09:00&quot;</span>, <span class="string">&quot;%Y-%m-%d %H:%M:%S %z&quot;</span>),
<span class="prelude-val">Ok</span>(<span class="ident">fixed_dt</span>.<span class="ident">clone</span>()));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">DateTime</span>::<span class="ident">parse_from_rfc2822</span>(<span class="string">&quot;Fri, 28 Nov 2014 21:00:09 +0900&quot;</span>),
<span class="prelude-val">Ok</span>(<span class="ident">fixed_dt</span>.<span class="ident">clone</span>()));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">DateTime</span>::<span class="ident">parse_from_rfc3339</span>(<span class="string">&quot;2014-11-28T21:00:09+09:00&quot;</span>), <span class="prelude-val">Ok</span>(<span class="ident">fixed_dt</span>.<span class="ident">clone</span>()));
<span class="comment">// method 3</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">datetime_from_str</span>(<span class="string">&quot;2014-11-28 12:00:09&quot;</span>, <span class="string">&quot;%Y-%m-%d %H:%M:%S&quot;</span>), <span class="prelude-val">Ok</span>(<span class="ident">dt</span>.<span class="ident">clone</span>()));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">datetime_from_str</span>(<span class="string">&quot;Fri Nov 28 12:00:09 2014&quot;</span>, <span class="string">&quot;%a %b %e %T %Y&quot;</span>), <span class="prelude-val">Ok</span>(<span class="ident">dt</span>.<span class="ident">clone</span>()));
<span class="comment">// oops, the year is missing!</span>
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">datetime_from_str</span>(<span class="string">&quot;Fri Nov 28 12:00:09&quot;</span>, <span class="string">&quot;%a %b %e %T %Y&quot;</span>).<span class="ident">is_err</span>());
<span class="comment">// oops, the format string does not include the year at all!</span>
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">datetime_from_str</span>(<span class="string">&quot;Fri Nov 28 12:00:09&quot;</span>, <span class="string">&quot;%a %b %e %T&quot;</span>).<span class="ident">is_err</span>());
<span class="comment">// oops, the weekday is incorrect!</span>
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">datetime_from_str</span>(<span class="string">&quot;Sat Nov 28 12:00:09 2014&quot;</span>, <span class="string">&quot;%a %b %e %T %Y&quot;</span>).<span class="ident">is_err</span>());</pre>
<h3 id='individual-date' class='section-header'><a href='#individual-date'>Individual date</a></h3>
<p>Chrono also provides an individual date type (<a href="./date/struct.Date.html"><strong><code>Date</code></strong></a>).
It also has time zones attached, and have to be constructed via time zones.
Most operations available to <code>DateTime</code> are also available to <code>Date</code> whenever appropriate.</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">chrono</span>::<span class="kw-2">*</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>::<span class="ident">today</span>(), <span class="ident">UTC</span>::<span class="ident">now</span>().<span class="ident">date</span>());
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">Local</span>::<span class="ident">today</span>(), <span class="ident">Local</span>::<span class="ident">now</span>().<span class="ident">date</span>());
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>).<span class="ident">weekday</span>(), <span class="ident">Weekday</span>::<span class="ident">Fri</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd_opt</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">31</span>), <span class="ident">LocalResult</span>::<span class="prelude-val">None</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">UTC</span>.<span class="ident">ymd</span>(<span class="number">2014</span>, <span class="number">11</span>, <span class="number">28</span>).<span class="ident">and_hms_milli</span>(<span class="number">7</span>, <span class="number">8</span>, <span class="number">9</span>, <span class="number">10</span>).<span class="ident">format</span>(<span class="string">&quot;%H%M%S&quot;</span>).<span class="ident">to_string</span>(),
<span class="string">&quot;070809&quot;</span>);</pre>
<p>There is no timezone-aware <code>Time</code> due to the lack of usefulness and also the complexity.</p>
<p><code>DateTime</code> has <a href="./datetime/struct.DateTime.html#method.date"><code>date</code></a> method
which returns a <code>Date</code> which represents its date component.
There is also a <a href="./datetime/struct.DateTime.html#method.time"><code>time</code></a> method,
which simply returns a naive local time described below.</p>
<h3 id='naive-date-and-time' class='section-header'><a href='#naive-date-and-time'>Naive date and time</a></h3>
<p>Chrono provides naive counterparts to <code>Date</code>, (non-existent) <code>Time</code> and <code>DateTime</code>
as <a href="./naive/date/struct.NaiveDate.html"><strong><code>NaiveDate</code></strong></a>,
<a href="./naive/time/struct.NaiveTime.html"><strong><code>NaiveTime</code></strong></a> and
<a href="./naive/datetime/struct.NaiveDateTime.html"><strong><code>NaiveDateTime</code></strong></a> respectively.</p>
<p>They have almost equivalent interfaces as their timezone-aware twins,
but are not associated to time zones obviously and can be quite low-level.
They are mostly useful for building blocks for higher-level types.</p>
<p>Timezone-aware <code>DateTime</code> and <code>Date</code> types have two methods returning naive versions:
<a href="./datetime/struct.DateTime.html#method.naive_local"><code>naive_local</code></a> returns
a view to the naive local time,
and <a href="./datetime/struct.DateTime.html#method.naive_utc"><code>naive_utc</code></a> returns
a view to the naive UTC time.</p>
<h2 id='limitations' class='section-header'><a href='#limitations'>Limitations</a></h2>
<p>Only proleptic Gregorian calendar (i.e. extended to support older dates) is supported.
Be very careful if you really have to deal with pre-20C dates, they can be in Julian or others.</p>
<p>Date types are limited in about +/- 262,000 years from the common epoch.
Time types are limited in the nanosecond accuracy.</p>
<p><a href="./naive/time/index.html#leap-second-handling">Leap seconds are supported in the representation but
Chrono doesn&#39;t try to make use of them</a>.
(The main reason is that leap seconds are not really predictable.)
Almost <em>every</em> operation over the possible leap seconds will ignore them.
Consider using <code>NaiveDateTime</code> with the implicit TAI (International Atomic Time) scale
if you want.</p>
<p>Chrono inherently does not support an inaccurate or partial date and time representation.
Any operation that can be ambiguous will return <code>None</code> in such cases.
For example, &quot;a month later&quot; of 2014-01-30 is not well-defined
and consequently <code>UTC.ymd(2014, 1, 30).with_month(2)</code> returns <code>None</code>.</p>
<p>Advanced time zone handling is not yet supported (but is planned in 0.3).</p>
</div><h2 id='reexports' class='section-header'><a href="#reexports">Reexports</a></h2>
<table><tr><td><code>pub use offset::<a class="trait" href="../chrono/offset/trait.TimeZone.html" title="trait chrono::offset::TimeZone">TimeZone</a>;</code></td></tr><tr><td><code>pub use offset::<a class="trait" href="../chrono/offset/trait.Offset.html" title="trait chrono::offset::Offset">Offset</a>;</code></td></tr><tr><td><code>pub use offset::<a class="enum" href="../chrono/offset/enum.LocalResult.html" title="enum chrono::offset::LocalResult">LocalResult</a>;</code></td></tr><tr><td><code>pub use offset::utc::<a class="struct" href="../chrono/offset/utc/struct.UTC.html" title="struct chrono::offset::utc::UTC">UTC</a>;</code></td></tr><tr><td><code>pub use offset::fixed::<a class="struct" href="../chrono/offset/fixed/struct.FixedOffset.html" title="struct chrono::offset::fixed::FixedOffset">FixedOffset</a>;</code></td></tr><tr><td><code>pub use offset::local::<a class="struct" href="../chrono/offset/local/struct.Local.html" title="struct chrono::offset::local::Local">Local</a>;</code></td></tr><tr><td><code>pub use naive::date::<a class="struct" href="../chrono/naive/date/struct.NaiveDate.html" title="struct chrono::naive::date::NaiveDate">NaiveDate</a>;</code></td></tr><tr><td><code>pub use naive::time::<a class="struct" href="../chrono/naive/time/struct.NaiveTime.html" title="struct chrono::naive::time::NaiveTime">NaiveTime</a>;</code></td></tr><tr><td><code>pub use naive::datetime::<a class="struct" href="../chrono/naive/datetime/struct.NaiveDateTime.html" title="struct chrono::naive::datetime::NaiveDateTime">NaiveDateTime</a>;</code></td></tr><tr><td><code>pub use date::<a class="struct" href="../chrono/date/struct.Date.html" title="struct chrono::date::Date">Date</a>;</code></td></tr><tr><td><code>pub use datetime::<a class="struct" href="../chrono/datetime/struct.DateTime.html" title="struct chrono::datetime::DateTime">DateTime</a>;</code></td></tr><tr><td><code>pub use format::<a class="struct" href="../chrono/format/struct.ParseError.html" title="struct chrono::format::ParseError">ParseError</a>;</code></td></tr><tr><td><code>pub use format::<a class="type" href="../chrono/format/type.ParseResult.html" title="type chrono::format::ParseResult">ParseResult</a>;</code></td></tr></table><h2 id='modules' class='section-header'><a href="#modules">Modules</a></h2>
<table>
<tr class=' module-item'>
<td><a class="mod" href="date/index.html"
title='mod chrono::date'>date</a></td>
<td class='docblock-short'>
<p>ISO 8601 calendar date with time zone.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="mod" href="datetime/index.html"
title='mod chrono::datetime'>datetime</a></td>
<td class='docblock-short'>
<p>ISO 8601 date and time with time zone.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="mod" href="duration/index.html"
title='mod chrono::duration'>duration</a></td>
<td class='docblock-short'>
<p>ISO 8601 duration.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="mod" href="format/index.html"
title='mod chrono::format'>format</a></td>
<td class='docblock-short'>
<p>Formatting utilities for date and time.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="mod" href="naive/index.html"
title='mod chrono::naive'>naive</a></td>
<td class='docblock-short'>
<p>Date and time types which do not concern about the timezones.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="mod" href="offset/index.html"
title='mod chrono::offset'>offset</a></td>
<td class='docblock-short'>
<p>The time zone, which calculates offsets from the local time to UTC.</p>
</td>
</tr></table><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
<tr class=' module-item'>
<td><a class="struct" href="struct.Duration.html"
title='struct chrono::Duration'>Duration</a></td>
<td class='docblock-short'>
<p>ISO 8601 time duration with nanosecond precision.
This also allows for the negative duration; see individual methods for details.</p>
</td>
</tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
<table>
<tr class=' module-item'>
<td><a class="enum" href="enum.Weekday.html"
title='enum chrono::Weekday'>Weekday</a></td>
<td class='docblock-short'>
<p>The day of week.</p>
</td>
</tr></table><h2 id='traits' class='section-header'><a href="#traits">Traits</a></h2>
<table>
<tr class=' module-item'>
<td><a class="trait" href="trait.Datelike.html"
title='trait chrono::Datelike'>Datelike</a></td>
<td class='docblock-short'>
<p>The common set of methods for date component.</p>
</td>
</tr>
<tr class=' module-item'>
<td><a class="trait" href="trait.Timelike.html"
title='trait chrono::Timelike'>Timelike</a></td>
<td class='docblock-short'>
<p>The common set of methods for time component.</p>
</td>
</tr></table></section>
<section id='search' class="content hidden"></section>
<section class="footer"></section>
<aside id="help" class="hidden">
<div>
<h1 class="hidden">Help</h1>
<div class="shortcuts">
<h2>Keyboard Shortcuts</h2>
<dl>
<dt>?</dt>
<dd>Show this help dialog</dd>
<dt>S</dt>
<dd>Focus the search field</dd>
<dt>&larrb;</dt>
<dd>Move up in search results</dd>
<dt>&rarrb;</dt>
<dd>Move down in search results</dd>
<dt>&#9166;</dt>
<dd>Go to active search result</dd>
<dt>+</dt>
<dd>Collapse/expand all sections</dd>
</dl>
</div>
<div class="infos">
<h2>Search Tricks</h2>
<p>
Prefix searches with a type followed by a colon (e.g.
<code>fn:</code>) to restrict the search to a given type.
</p>
<p>
Accepted types are: <code>fn</code>, <code>mod</code>,
<code>struct</code>, <code>enum</code>,
<code>trait</code>, <code>type</code>, <code>macro</code>,
and <code>const</code>.
</p>
<p>
Search functions by type signature (e.g.
<code>vec -> usize</code> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
<script>
window.rootPath = "../";
window.currentCrate = "chrono";
</script>
<script src="../main.js"></script>
<script defer src="../search-index.js"></script>
</body>
</html>
Reference in New Issue Copy Permalink