138 lines
16 KiB
HTML
138 lines
16 KiB
HTML
|
<!DOCTYPE html>
|
||
|
|
<html>
|
||
|
|
<!-- Created by GNU Texinfo 7.1, https://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<!-- This manual documents Guile version 3.0.10.
|
||
|
|
|
||
|
|
Copyright (C) 1996-1997, 2000-2005, 2009-2023 Free Software Foundation,
|
||
|
|
Inc.
|
||
|
|
|
||
|
|
Copyright (C) 2021 Maxime Devos
|
||
|
|
|
||
|
|
Copyright (C) 2024 Tomas Volf
|
||
|
|
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
||
|
|
any later version published by the Free Software Foundation; with no
|
||
|
|
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
|
||
|
|
copy of the license is included in the section entitled "GNU Free
|
||
|
|
Documentation License." -->
|
||
|
|
<title>SRFI-19 Time/Date conversions (Guile Reference Manual)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="SRFI-19 Time/Date conversions (Guile Reference Manual)">
|
||
|
|
<meta name="keywords" content="SRFI-19 Time/Date conversions (Guile Reference Manual)">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content=".texi2any-real">
|
||
|
|
<meta name="viewport" content="width=device-width,initial-scale=1">
|
||
|
|
|
||
|
|
<link href="index.html" rel="start" title="Top">
|
||
|
|
<link href="Concept-Index.html" rel="index" title="Concept Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="SRFI_002d19.html" rel="up" title="SRFI-19">
|
||
|
|
<link href="SRFI_002d19-Date-to-string.html" rel="next" title="SRFI-19 Date to string">
|
||
|
|
<link href="SRFI_002d19-Date.html" rel="prev" title="SRFI-19 Date">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em}
|
||
|
|
span:hover a.copiable-link {visibility: visible}
|
||
|
|
strong.def-name {font-family: monospace; font-weight: bold; font-size: larger}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
<link rel="stylesheet" type="text/css" href="https://www.gnu.org/software/gnulib/manual.css">
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<div class="subsubsection-level-extent" id="SRFI_002d19-Time_002fDate-conversions">
|
||
|
|
<div class="nav-panel">
|
||
|
|
<p>
|
||
|
|
Next: <a href="SRFI_002d19-Date-to-string.html" accesskey="n" rel="next">SRFI-19 Date to string</a>, Previous: <a href="SRFI_002d19-Date.html" accesskey="p" rel="prev">SRFI-19 Date</a>, Up: <a href="SRFI_002d19.html" accesskey="u" rel="up">SRFI-19 - Time/Date Library</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<h4 class="subsubsection" id="SRFI_002d19-Time_002fDate-conversions-1"><span>7.5.16.4 SRFI-19 Time/Date conversions<a class="copiable-link" href="#SRFI_002d19-Time_002fDate-conversions-1"> ¶</a></span></h4>
|
||
|
|
<a class="index-entry-id" id="index-time-conversion"></a>
|
||
|
|
<a class="index-entry-id" id="index-date-conversion"></a>
|
||
|
|
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-date_002d_003ejulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">date->julian-day</strong> <var class="def-var-arguments">date</var><a class="copiable-link" href="#index-date_002d_003ejulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-date_002d_003emodified_002djulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">date->modified-julian-day</strong> <var class="def-var-arguments">date</var><a class="copiable-link" href="#index-date_002d_003emodified_002djulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-date_002d_003etime_002dmonotonic"><span class="category-def">Function: </span><span><strong class="def-name">date->time-monotonic</strong> <var class="def-var-arguments">date</var><a class="copiable-link" href="#index-date_002d_003etime_002dmonotonic"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-date_002d_003etime_002dtai"><span class="category-def">Function: </span><span><strong class="def-name">date->time-tai</strong> <var class="def-var-arguments">date</var><a class="copiable-link" href="#index-date_002d_003etime_002dtai"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-date_002d_003etime_002dutc"><span class="category-def">Function: </span><span><strong class="def-name">date->time-utc</strong> <var class="def-var-arguments">date</var><a class="copiable-link" href="#index-date_002d_003etime_002dutc"> ¶</a></span></dt>
|
||
|
|
</dl>
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-julian_002dday_002d_003edate"><span class="category-def">Function: </span><span><strong class="def-name">julian-day->date</strong> <var class="def-var-arguments">jdn [tz-offset]</var><a class="copiable-link" href="#index-julian_002dday_002d_003edate"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-julian_002dday_002d_003etime_002dmonotonic"><span class="category-def">Function: </span><span><strong class="def-name">julian-day->time-monotonic</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-julian_002dday_002d_003etime_002dmonotonic"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-julian_002dday_002d_003etime_002dtai"><span class="category-def">Function: </span><span><strong class="def-name">julian-day->time-tai</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-julian_002dday_002d_003etime_002dtai"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-julian_002dday_002d_003etime_002dutc"><span class="category-def">Function: </span><span><strong class="def-name">julian-day->time-utc</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-julian_002dday_002d_003etime_002dutc"> ¶</a></span></dt>
|
||
|
|
</dl>
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-modified_002djulian_002dday_002d_003edate"><span class="category-def">Function: </span><span><strong class="def-name">modified-julian-day->date</strong> <var class="def-var-arguments">jdn [tz-offset]</var><a class="copiable-link" href="#index-modified_002djulian_002dday_002d_003edate"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-modified_002djulian_002dday_002d_003etime_002dmonotonic"><span class="category-def">Function: </span><span><strong class="def-name">modified-julian-day->time-monotonic</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-modified_002djulian_002dday_002d_003etime_002dmonotonic"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-modified_002djulian_002dday_002d_003etime_002dtai"><span class="category-def">Function: </span><span><strong class="def-name">modified-julian-day->time-tai</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-modified_002djulian_002dday_002d_003etime_002dtai"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-modified_002djulian_002dday_002d_003etime_002dutc"><span class="category-def">Function: </span><span><strong class="def-name">modified-julian-day->time-utc</strong> <var class="def-var-arguments">jdn</var><a class="copiable-link" href="#index-modified_002djulian_002dday_002d_003etime_002dutc"> ¶</a></span></dt>
|
||
|
|
</dl>
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-time_002dmonotonic_002d_003edate"><span class="category-def">Function: </span><span><strong class="def-name">time-monotonic->date</strong> <var class="def-var-arguments">time [tz-offset]</var><a class="copiable-link" href="#index-time_002dmonotonic_002d_003edate"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dmonotonic_002d_003etime_002dtai"><span class="category-def">Function: </span><span><strong class="def-name">time-monotonic->time-tai</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dmonotonic_002d_003etime_002dtai"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dmonotonic_002d_003etime_002dtai_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-monotonic->time-tai!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dmonotonic_002d_003etime_002dtai_0021"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dmonotonic_002d_003etime_002dutc"><span class="category-def">Function: </span><span><strong class="def-name">time-monotonic->time-utc</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dmonotonic_002d_003etime_002dutc"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dmonotonic_002d_003etime_002dutc_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-monotonic->time-utc!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dmonotonic_002d_003etime_002dutc_0021"> ¶</a></span></dt>
|
||
|
|
</dl>
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-time_002dtai_002d_003edate"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->date</strong> <var class="def-var-arguments">time [tz-offset]</var><a class="copiable-link" href="#index-time_002dtai_002d_003edate"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003ejulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->julian-day</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003ejulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003emodified_002djulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->modified-julian-day</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003emodified_002djulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003etime_002dmonotonic"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->time-monotonic</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003etime_002dmonotonic"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003etime_002dmonotonic_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->time-monotonic!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003etime_002dmonotonic_0021"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003etime_002dutc"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->time-utc</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003etime_002dutc"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dtai_002d_003etime_002dutc_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-tai->time-utc!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dtai_002d_003etime_002dutc_0021"> ¶</a></span></dt>
|
||
|
|
</dl>
|
||
|
|
<dl class="first-deffn first-defun-alias-first-deffn">
|
||
|
|
<dt class="deffn defun-alias-deffn" id="index-time_002dutc_002d_003edate"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->date</strong> <var class="def-var-arguments">time [tz-offset]</var><a class="copiable-link" href="#index-time_002dutc_002d_003edate"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003ejulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->julian-day</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003ejulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003emodified_002djulian_002dday"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->modified-julian-day</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003emodified_002djulian_002dday"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003etime_002dmonotonic"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->time-monotonic</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003etime_002dmonotonic"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003etime_002dmonotonic_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->time-monotonic!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003etime_002dmonotonic_0021"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003etime_002dtai"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->time-tai</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003etime_002dtai"> ¶</a></span></dt>
|
||
|
|
<dt class="deffnx defunx-alias-deffnx def-cmd-deffn" id="index-time_002dutc_002d_003etime_002dtai_0021"><span class="category-def">Function: </span><span><strong class="def-name">time-utc->time-tai!</strong> <var class="def-var-arguments">time</var><a class="copiable-link" href="#index-time_002dutc_002d_003etime_002dtai_0021"> ¶</a></span></dt>
|
||
|
|
<dd><br>
|
||
|
|
<p>Convert between dates, times and days of the respective types. For
|
||
|
|
instance <code class="code">time-tai->time-utc</code> accepts a <var class="var">time</var> object of type
|
||
|
|
<code class="code">time-tai</code> and returns an object of type <code class="code">time-utc</code>.
|
||
|
|
</p>
|
||
|
|
<p>The <code class="code">!</code> variants may modify their <var class="var">time</var> argument to form
|
||
|
|
their return. The plain functions create a new object.
|
||
|
|
</p>
|
||
|
|
<p>For conversions to dates, <var class="var">tz-offset</var> is seconds east of
|
||
|
|
Greenwich. The default is the local timezone, at the given time, as
|
||
|
|
provided by the system, using <code class="code">localtime</code> (see <a class="pxref" href="Time.html">Time</a>).
|
||
|
|
</p>
|
||
|
|
<p>On 32-bit systems, <code class="code">localtime</code> is limited to a 32-bit
|
||
|
|
<code class="code">time_t</code>, so a default <var class="var">tz-offset</var> is only available for
|
||
|
|
times between Dec 1901 and Jan 2038. For prior dates an application
|
||
|
|
might like to use the value in 1902, though some locations have zone
|
||
|
|
changes prior to that. For future dates an application might like to
|
||
|
|
assume today’s rules extend indefinitely. But for correct daylight
|
||
|
|
savings transitions it will be necessary to take an offset for the
|
||
|
|
same day and time but a year in range and which has the same starting
|
||
|
|
weekday and same leap/non-leap (to support rules like last Sunday in
|
||
|
|
October).
|
||
|
|
</p></dd></dl>
|
||
|
|
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<div class="nav-panel">
|
||
|
|
<p>
|
||
|
|
Next: <a href="SRFI_002d19-Date-to-string.html">SRFI-19 Date to string</a>, Previous: <a href="SRFI_002d19-Date.html">SRFI-19 Date</a>, Up: <a href="SRFI_002d19.html">SRFI-19 - Time/Date Library</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|