NAME | DESCRIPTION | DISPLAYING TIME SPANS | PARSING TIME SPANS | DISPLAYING TIMESTAMPS | PARSING TIMESTAMPS | CALENDAR EVENTS | SEE ALSO | COLOPHON

SYSTEMD.TIME(7)                 systemd.time                 SYSTEMD.TIME(7)

NAME         top

       systemd.time - Time and date specifications

DESCRIPTION         top

       In systemd, timestamps, time spans, and calendar events are displayed
       and may be specified in closely related syntaxes.

DISPLAYING TIME SPANS         top

       Time spans refer to time durations. On display, systemd will present
       time spans as a space-separated series of time values each suffixed
       by a time unit.

           2h 30min

       All specified time values are meant to be added up. The above hence
       refers to 150 minutes.

PARSING TIME SPANS         top

       When parsing, systemd will accept the same time span syntax.
       Separating spaces may be omitted. The following time units are
       understood:

       ·   usec, us

       ·   msec, ms

       ·   seconds, second, sec, s

       ·   minutes, minute, min, m

       ·   hours, hour, hr, h

       ·   days, day, d

       ·   weeks, week, w

       ·   months, month, M (defined as 30.44 days)

       ·   years, year, y (define as 365.25 days)

       If no time unit is specified, generally seconds are assumed, but some
       exceptions exist and are marked as such. In a few cases "ns", "nsec"
       is accepted too, where the granularity of the time span allows for
       this.

       Examples for valid time span specifications:

           2 h
           2hours
           48hr
           1y 12month
           55s500ms
           300ms20s 5day

DISPLAYING TIMESTAMPS         top

       Timestamps refer to specific, unique points in time. On display,
       systemd will format these in the local timezone as follows:

           Fri 2012-11-23 23:02:15 CET

       The weekday is printed according to the locale choice of the user.

PARSING TIMESTAMPS         top

       When parsing, systemd will accept a similar syntax, but expects no
       timezone specification, unless it is given as the literal string
       "UTC". In this case, the time is considered in UTC, otherwise in the
       local timezone. The weekday specification is optional, but when the
       weekday is specified, it must either be in the abbreviated ("Wed") or
       non-abbreviated ("Wednesday") 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, respectively, is assumed. The seconds component of
       the time may also be omitted, in which case ":00" is assumed. Year
       numbers may be specified in full or may be abbreviated (omitting the
       century).

       A timestamp is considered invalid if a weekday is specified and the
       date does not actually match the specified day of the week.

       When parsing, systemd will also accept a few special placeholders
       instead of timestamps: "now" may be used to refer to the current time
       (or of the invocation of the command that is currently executed).
       "today", "yesterday", and "tomorrow" refer to 00:00:00 of the current
       day, the day before, or the next day, respectively.

       When parsing, systemd will also accept relative time specifications.
       A time span (see above) that is prefixed with "+" is evaluated to the
       current time plus the specified time span. Correspondingly, a time
       span that is prefixed with "-" is evaluated to the current time minus
       the specified time span. Instead of prefixing the time span with "+"
       or "-", it may also be suffixed with a space and the word "left" or
       "ago".

       Finally, a timespan prefixed with "@" is evaluated relative to the
       UNIX time epoch 1st Jan, 1970, 00:00.

       Examples for valid timestamps and their normalized form (assuming the
       current time was 2012-11-23 18:15:22 and the timezone was UTC+8, for
       example TZ=Asia/Shanghai):

           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
                  11:12:13.9900009 → Fri 2012-11-23 11:12:13
                                     format_timestamp_us: Fri 2012-11-23 11:12:13.990000
                             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
                      +3h30min UTC → -EINVAL
                               -5s → Fri 2012-11-23 18:15:17
                         11min ago → Fri 2012-11-23 18:04:22
                     11min ago UTC → -EINVAL
                       @1395716396 → Tue 2014-03-25 03:59:56

       Note that timestamps printed by systemd will not be parsed correctly
       by systemd, as the timezone specification is not accepted, and
       printing timestamps is subject to locale settings for the weekday,
       while parsing only accepts English weekday names.

       In some cases, systemd will display a relative timestamp (relative to
       the current time, or the time of invocation of the command) instead
       or in addition to an absolute timestamp as described above. A
       relative timestamp is formatted as follows:

       2 months 5 days ago

       Note that any relative timestamp will also parse correctly where a
       timestamp is expected. (see above)

CALENDAR EVENTS         top

       Calendar events may be used to refer to one or more points in time in
       a single expression. They form a superset of the absolute timestamps
       explained above:

           Thu,Fri 2012-*-1,5 11:12:13

       The above refers to 11:12:13 of the first or fifth day of any month
       of the year 2012, but only if that day is a Thursday or Friday.

       The weekday specification is optional. If specified, it should
       consist of one or more English language weekday names, either in the
       abbreviated (Wed) or non-abbreviated (Wednesday) form (case does not
       matter), separated by commas. Specifying two weekdays separated by
       ".."  refers to a range of continuous weekdays.  "," and ".."  may be
       combined freely.

       In the date and time specifications, any component may be specified
       as "*" 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 "/" 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 "..".

       The seconds component may contain decimal fractions both in the value
       and the repetition. All fractions are rounded to 6 decimal places.

       Either time or date specification may be omitted, in which case the
       current day and 00:00:00 is implied, respectively. If the second
       component is not specified, ":00" is assumed.

       A timezone specification is not expected, unless it is given as the
       literal string "UTC", similarly to timestamps.

       The special expressions "minutely", "hourly", "daily", "monthly",
       "weekly", "yearly", "quarterly", "semiannually" may be used as
       calendar events which refer to "*-*-* *:*:00", "*-*-* *:00:00",
       "*-*-* 00:00:00", "*-*-01 00:00:00", "Mon *-*-* 00:00:00",
       "*-01-01 00:00:00", "*-01,04,07,10-01 00:00:00" and "*-01,07-01
       00:00:00", respectively.

       Examples for valid timestamps and their normalized form:

              Sat,Thu,Mon..Wed,Sat..Sun → Mon..Thu,Sat,Sun *-*-* 00:00:00
                Mon,Sun 12-*-* 2,1:23 → Mon,Sun 2012-*-* 01,02:23:00
                              Wed *-1 → Wed *-*-01 00:00:00
                      Wed..Wed,Wed *-1 → Wed *-*-01 00:00:00
                           Wed, 17:48 → Wed *-*-* 17:48:00
           Wed..Sat,Tue 12-10-15 1:2:3 → Tue..Sat 2012-10-15 01:02:03
                          *-*-7 0:0:0 → *-*-07 00:00:00
                                10-15 → *-10-15 00:00:00
                  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
            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
                                05:40 → *-*-* 05:40:00
               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
                 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
                               hourly → *-*-* *:00:00
                                daily → *-*-* 00:00:00
                            daily UTC → *-*-* 00:00:00 UTC
                              monthly → *-*-01 00:00:00
                               weekly → Mon *-*-* 00:00:00
                               yearly → *-01-01 00:00:00
                             annually → *-01-01 00:00:00
                                *:2/3 → *-*-* *:02/3:00

       Calendar events are used by timer units, see systemd.timer(5) for
       details.

SEE ALSO         top

       systemd(1), journalctl(1), systemd.timer(5), systemd.unit(5),
       systemd.directives(7)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see 
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨https://github.com/systemd/systemd.git⟩ on 2016-07-16.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 230                                                  SYSTEMD.TIME(7)