| <!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="Formatting (and parsing) utilities for date and time."><meta name="keywords" content="rust, rustlang, rust-lang, format"><title>chrono::format - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc mod"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../chrono/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../chrono/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Module format</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#reexports">Re-exports</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="#functions">Functions</a></li><li><a href="#types">Type Definitions</a></li></ul></section></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Module <a href="../index.html">chrono</a>::<wbr><a class="mod" href="#">format</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/chrono/format/mod.rs.html#4-1082">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Formatting (and parsing) utilities for date and time.</p> |
| <p>This module provides the common types and routines to implement, |
| for example, <a href="../struct.DateTime.html#method.format"><code>DateTime::format</code></a> or |
| <a href="../struct.DateTime.html#method.parse_from_str"><code>DateTime::parse_from_str</code></a> methods. |
| For most cases you should use these high-level interfaces.</p> |
| <p>Internally the formatting and parsing shares the same abstract <strong>formatting items</strong>, |
| which are just an <a href="https://doc.rust-lang.org/std/iter/trait.Iterator.html"><code>Iterator</code></a> of |
| the <a href="./enum.Item.html"><code>Item</code></a> type. |
| They are generated from more readable <strong>format strings</strong>; |
| currently Chrono supports a built-in syntax closely resembling |
| C’s <code>strftime</code> format. The available options can be found <a href="./strftime/index.html">here</a>.</p> |
| <h2 id="example"><a href="#example">Example</a></h2> |
| <div class="example-wrap ignore"><div class='tooltip'>ⓘ</div><pre class="rust rust-example-rendered"><code><span class="kw">use </span>chrono::{TimeZone, Utc}; |
| |
| <span class="kw">let </span>date_time = Utc.with_ymd_and_hms(<span class="number">2020</span>, <span class="number">11</span>, <span class="number">10</span>, <span class="number">0</span>, <span class="number">1</span>, <span class="number">32</span>).unwrap(); |
| |
| <span class="kw">let </span>formatted = <span class="macro">format!</span>(<span class="string">"{}"</span>, date_time.format(<span class="string">"%Y-%m-%d %H:%M:%S"</span>)); |
| <span class="macro">assert_eq!</span>(formatted, <span class="string">"2020-11-10 00:01:32"</span>); |
| |
| <span class="kw">let </span>parsed = Utc.datetime_from_str(<span class="kw-2">&</span>formatted, <span class="string">"%Y-%m-%d %H:%M:%S"</span>)<span class="question-mark">?</span>; |
| <span class="macro">assert_eq!</span>(parsed, date_time);</code></pre></div> |
| </div></details><h2 id="reexports" class="small-section-header"><a href="#reexports">Re-exports</a></h2><div class="item-table"><div class="item-row"><div class="item-left import-item" id="reexport.StrftimeItems"><code>pub use strftime::<a class="struct" href="strftime/struct.StrftimeItems.html" title="struct chrono::format::strftime::StrftimeItems">StrftimeItems</a>;</code></div></div></div><h2 id="modules" class="small-section-header"><a href="#modules">Modules</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="mod" href="strftime/index.html" title="chrono::format::strftime mod">strftime</a></div><div class="item-right docblock-short"><code>strftime</code>/<code>strptime</code>-inspired date and time formatting syntax.</div></div></div><h2 id="structs" class="small-section-header"><a href="#structs">Structs</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.InternalFixed.html" title="chrono::format::InternalFixed struct">InternalFixed</a></div><div class="item-right docblock-short">An opaque type representing fixed-format item types for internal uses only.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.InternalNumeric.html" title="chrono::format::InternalNumeric struct">InternalNumeric</a></div><div class="item-right docblock-short">An opaque type representing numeric item types for internal uses only.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ParseError.html" title="chrono::format::ParseError struct">ParseError</a></div><div class="item-right docblock-short">An error from the <code>parse</code> function.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Parsed.html" title="chrono::format::Parsed struct">Parsed</a></div><div class="item-right docblock-short">Parsed parts of date and time. There are two classes of methods:</div></div></div><h2 id="enums" class="small-section-header"><a href="#enums">Enums</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Fixed.html" title="chrono::format::Fixed enum">Fixed</a></div><div class="item-right docblock-short">Fixed-format item types.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Item.html" title="chrono::format::Item enum">Item</a></div><div class="item-right docblock-short">A single formatting item. This is used for both formatting and parsing.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Numeric.html" title="chrono::format::Numeric enum">Numeric</a></div><div class="item-right docblock-short">Numeric item types. |
| They have associated formatting width (FW) and parsing width (PW).</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Pad.html" title="chrono::format::Pad enum">Pad</a></div><div class="item-right docblock-short">Padding characters for numeric items.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.ParseErrorKind.html" title="chrono::format::ParseErrorKind enum">ParseErrorKind</a></div><div class="item-right docblock-short">The category of parse error</div></div></div><h2 id="functions" class="small-section-header"><a href="#functions">Functions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse.html" title="chrono::format::parse fn">parse</a></div><div class="item-right docblock-short">Tries to parse given string into <code>parsed</code> with given formatting items. |
| Returns <code>Ok</code> when the entire string has been parsed (otherwise <code>parsed</code> should not be used). |
| There should be no trailing string after parsing; |
| use a stray <a href="./enum.Item.html#variant.Space"><code>Item::Space</code></a> to trim whitespaces.</div></div><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse_and_remainder.html" title="chrono::format::parse_and_remainder fn">parse_and_remainder</a></div><div class="item-right docblock-short">Tries to parse given string into <code>parsed</code> with given formatting items. |
| Returns <code>Ok</code> with a slice of the unparsed remainder.</div></div></div><h2 id="types" class="small-section-header"><a href="#types">Type Definitions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="type" href="type.ParseResult.html" title="chrono::format::ParseResult type">ParseResult</a></div><div class="item-right docblock-short">Same as <code>Result<T, ParseError></code>.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="chrono" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
