<?xml version='1.0'?> <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
-<!--
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="systemd.time">
<refentryinfo>
<title>systemd.time</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
understood:</para>
<itemizedlist>
- <listitem><para>usec, us</para></listitem>
+ <listitem><para>usec, us, µs</para></listitem>
<listitem><para>msec, ms</para></listitem>
<listitem><para>seconds, second, sec, s</para></listitem>
<listitem><para>minutes, minute, min, m</para></listitem>
1y 12month
55s500ms
300ms20s 5day</programlisting>
+
+ <para>One can use the <command>timespan</command> command of
+ <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ to normalise a textual time span for testing and validation purposes.</para>
</refsect1>
<refsect1>
<title>Parsing Timestamps</title>
<para>When parsing, systemd will accept a similar syntax, but expects no timezone specification, unless it is given
- as the literal string <literal>UTC</literal> (for the UTC timezone) or is specified to be the locally configured
- timezone. Other timezones than the local and UTC are not supported. The weekday specification is optional, but when
+ as the literal string <literal>UTC</literal> (for the UTC timezone), or is specified to be the locally configured
+ timezone, or the timezone name in the IANA timezone database format. The complete list of timezones
+ supported on your system can be obtained using the <literal>timedatectl list-timezones</literal>
+ (see <citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>).
+ Using IANA format is recommended over local timezone names, as less prone to errors (eg: with local timezone it's possible to
+ specify daylight saving time in winter, while it's incorrect). The weekday specification is optional, but when
the weekday is specified, it must either be in the abbreviated (<literal>Wed</literal>) or non-abbreviated
(<literal>Wednesday</literal>) English language form (case does not matter), and is not subject to the locale
choice of the user. Either the date, or the time part may be omitted, in which case the current date or 00:00:00,
(assuming the current time was 2012-11-23 18:15:22 and the timezone
was UTC+8, for example TZ=Asia/Shanghai):</para>
- <programlisting>Fri 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
- 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
-2012-11-23 11:12:13 UTC → Fri 2012-11-23 19:12:13
- 2012-11-23 → Fri 2012-11-23 00:00:00
- 12-11-23 → Fri 2012-11-23 00:00:00
- 11:12:13 → Fri 2012-11-23 11:12:13
- 11:12 → Fri 2012-11-23 11:12:00
- now → Fri 2012-11-23 18:15:22
- today → Fri 2012-11-23 00:00:00
- today UTC → Fri 2012-11-23 16:00:00
- yesterday → Fri 2012-11-22 00:00:00
- tomorrow → Fri 2012-11-24 00:00:00
- +3h30min → Fri 2012-11-23 21:45:22
- -5s → Fri 2012-11-23 18:15:17
- 11min ago → Fri 2012-11-23 18:04:22
- @1395716396 → Tue 2014-03-25 03:59:56</programlisting>
+ <programlisting> Fri 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
+ 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
+ 2012-11-23 11:12:13 UTC → Fri 2012-11-23 19:12:13
+ 2012-11-23 → Fri 2012-11-23 00:00:00
+ 12-11-23 → Fri 2012-11-23 00:00:00
+ 11:12:13 → Fri 2012-11-23 11:12:13
+ 11:12 → Fri 2012-11-23 11:12:00
+ now → Fri 2012-11-23 18:15:22
+ today → Fri 2012-11-23 00:00:00
+ today UTC → Fri 2012-11-23 16:00:00
+ yesterday → Fri 2012-11-22 00:00:00
+ tomorrow → Fri 2012-11-24 00:00:00
+tomorrow Pacific/Auckland → Thu 2012-11-23 19:00:00
+ +3h30min → Fri 2012-11-23 21:45:22
+ -5s → Fri 2012-11-23 18:15:17
+ 11min ago → Fri 2012-11-23 18:04:22
+ @1395716396 → Tue 2014-03-25 03:59:56</programlisting>
<para>Note that timestamps displayed by remote systems with a non-matching timezone are usually not parsable
locally, as the timezone component is not understood (unless it happens to be <literal>UTC</literal>).</para>
<programlisting>2 months 5 days ago</programlisting>
<para>Note that a relative timestamp is also accepted where a timestamp is expected (see above).</para>
+
+ <para>Use the <command>timestamp</command> command of
+ <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry> to
+ validate and normalize timestamps for testing purposes.</para>
</refsect1>
<refsect1>
<para>In the date and time specifications, any component may be
specified as <literal>*</literal> in which case any value will
match. Alternatively, each component can be specified as a list of
- values separated by commas. Values may also be suffixed with
+ values separated by commas. Values may be suffixed with
<literal>/</literal> and a repetition value, which indicates that
the value itself and the value plus all multiples of the repetition value
- are matched. Each component may also contain a range of values
- separated by <literal>..</literal>.</para>
+ are matched. Two values separated by <literal>..</literal> may be used
+ to indicate a range of values; ranges may also be followed with
+ <literal>/</literal> and a repetition value.</para>
+
+ <para>A date specification may use <literal>~</literal> to indicate the
+ last day(s) in a month. For example, <literal>*-02~03</literal> means
+ "the third last day in February," and <literal>Mon *-05~07/1</literal>
+ means "the last Monday in May."</para>
<para>The seconds component may contain decimal fractions both in
the value and the repetition. All fractions are rounded to 6
second component is not specified, <literal>:00</literal> is
assumed.</para>
- <para>A timezone specification is not expected, unless it is given as the literal string <literal>UTC</literal>, or
- the local timezone, similar to the supported syntax of timestamps (see above). Non-local timezones except for UTC
- are not supported.</para>
-
- <para>The special expressions
- <literal>minutely</literal>,
- <literal>hourly</literal>, <literal>daily</literal>,
- <literal>monthly</literal>, <literal>weekly</literal>,
- <literal>yearly</literal>,
- <literal>quarterly</literal>,
- <literal>semiannually</literal> may be used as
- calendar events which refer to
- <literal>*-*-* *:*:00</literal>,
- <literal>*-*-* *:00:00</literal>,
- <literal>*-*-* 00:00:00</literal>,
- <literal>*-*-01 00:00:00</literal>,
- <literal>Mon *-*-* 00:00:00</literal>,
- <literal>*-01-01 00:00:00</literal>,
- <literal>*-01,04,07,10-01 00:00:00</literal> and
- <literal>*-01,07-01 00:00:00</literal>, respectively.
- </para>
+ <para>Timezone can be specified as the literal string <literal>UTC</literal>, or
+ the local timezone, similar to the supported syntax of timestamps (see above), or the timezone
+ in the IANA timezone database format (also see above).</para>
+
+ <para>The following special expressions may be used as shorthands for longer normalized forms:</para>
+
+ <programlisting> minutely → *-*-* *:*:00
+ hourly → *-*-* *:00:00
+ daily → *-*-* 00:00:00
+ monthly → *-*-01 00:00:00
+ weekly → Mon *-*-* 00:00:00
+ yearly → *-01-01 00:00:00
+ quarterly → *-01,04,07,10-01 00:00:00
+semiannually → *-01,07-01 00:00:00
+ </programlisting>
<para>Examples for valid timestamps and their
normalized form:</para>
monday *-12-* 17:00 → Mon *-12-* 17:00:00
Mon,Fri *-*-3,1,2 *:30:45 → Mon,Fri *-*-01,02,03 *:30:45
12,14,13,12:20,10,30 → *-*-* 12,13,14:10,20,30:00
- 12..14:10,20,30 → *-*-* 12,13,14:10,20,30:00
+ 12..14:10,20,30 → *-*-* 12..14:10,20,30:00
mon,fri *-1/2-1,3 *:30:45 → Mon,Fri *-01/2-01,03 *:30:45
03-05 08:05:40 → *-03-05 08:05:40
08:05:40 → *-*-* 08:05:40
Sat,Sun 12-05 08:05:40 → Sat,Sun *-12-05 08:05:40
Sat,Sun 08:05:40 → Sat,Sun *-*-* 08:05:40
2003-03-05 05:40 → 2003-03-05 05:40:00
- 05:40:23.4200004/3.1700005 → 05:40:23.420000/3.170001
- 2003-02..04-05 → 2003-02,03,04-05 00:00:00
+ 05:40:23.4200004/3.1700005 → *-*-* 05:40:23.420000/3.170001
+ 2003-02..04-05 → 2003-02..04-05 00:00:00
2003-03-05 05:40 UTC → 2003-03-05 05:40:00 UTC
2003-03-05 → 2003-03-05 00:00:00
03-05 → *-03-05 00:00:00
daily UTC → *-*-* 00:00:00 UTC
monthly → *-*-01 00:00:00
weekly → Mon *-*-* 00:00:00
+ weekly Pacific/Auckland → Mon *-*-* 00:00:00 Pacific/Auckland
yearly → *-01-01 00:00:00
annually → *-01-01 00:00:00
*:2/3 → *-*-* *:02/3:00</programlisting>
<citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details.</para>
+ <para>Use the <command>calendar</command> command of
+ <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry> to validate
+ and normalize calendar time specifications for testing purposes. The tool also calculates when a specified
+ calendar event would elapse next.</para>
</refsect1>
<refsect1>
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
projects / thirdparty / systemd.git / blobdiff