SYSTEMD.TIME(7)                                   SYSTEMD.TIME(7)

     NAME
          systemd.time - Time and date specifications

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

     DISPLAYING TIME SPANS
          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. Example:

              2h 30min

          All specified time values are meant to be added up. The
          above hence refers to 150 minutes. Display is
          locale-independent, only English names for the time units
          are used.

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

          +o   usec, us, mcs

          +o   msec, ms

          +o   seconds, second, sec, s

          +o   minutes, minute, min, m

          +o   hours, hour, hr, h

          +o   days, day, d

          +o   weeks, week, w

          +o   months, month, M (defined as 30.44 days)

          +o   years, year, y (defined 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 permits this. Parsing is generally
          locale-independent, non-English names for the time units are
          not accepted.

          Examples for valid time span specifications:

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     SYSTEMD.TIME(7)                                   SYSTEMD.TIME(7)

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

          One can use the timespan command of systemd-analyze(1) to
          normalise a textual time span for testing and validation
          purposes.

          Internally, systemd generally operates with microsecond time
          granularity, while the default time unit in
          user-configurable time spans is usually seconds (see above).
          This disparity becomes visible when comparing the same
          settings in the (high-level) unit file syntax with the
          matching (more low-level) D-Bus properties (which are what
          systemctl(1)'s show command displays). The former typically
          are suffixed with "...Sec" to indicate the default unit of
          seconds, the latter are typically suffixed with "...USec" to
          indicate the underlying low-level time unit, even if they
          both encapsulate the very same settings.

     DISPLAYING TIMESTAMPS
          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 in the abbreviated English language
          form. The formatting is locale-independent.

          In some cases timestamps are shown in the UTC timezone
          instead of the local timezone, which is indicated via the
          "UTC" timezone specifier in the output.

          In some cases timestamps are shown with microsecond
          granularity. In this case the sub-second remainder is
          separated by a full stop from the seconds component.

     PARSING TIMESTAMPS
          When parsing, systemd will accept a similar syntax, but
          expects no timezone specification, unless it is given as the
          literal string "UTC" (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
          "timedatectl list-timezones" (see timedatectl(1)). Using
          IANA format is recommended over local timezone names, as
          less prone to errors (e.g. with local timezone it's possible
          to specify daylight saving time in winter, even though that

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     SYSTEMD.TIME(7)                                   SYSTEMD.TIME(7)

          is not correct). 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 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 → 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

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     SYSTEMD.TIME(7)                                   SYSTEMD.TIME(7)

                              11min ago → Fri 2012-11-23 18:04:22
                            @1395716396 → Tue 2014-03-25 03:59:56

          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 "UTC").

          Timestamps may also be specified with microsecond
          granularity. The sub-second remainder is expected separated
          by a full stop from the seconds component. Example:

              2014-03-25 03:59:56.654563

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

              2 months 5 days ago

          Note that a relative timestamp is also accepted where a
          timestamp is expected (see above).

          Use the timestamp command of systemd-analyze(1) to validate
          and normalize timestamps for testing purposes.

     CALENDAR EVENTS
          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 be suffixed with "/"
          and a repetition value, which indicates that the value

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          itself and the value plus all multiples of the repetition
          value are matched. Two values separated by ".."  may be used
          to indicate a range of values; ranges may also be followed
          with "/" and a repetition value, in which case the
          expression matches all times starting with the start value,
          and continuing with all multiples of the repetition value
          relative to the start value, ending at the end value the
          latest.

          A date specification may use "~" to indicate the last day(s)
          in a month. For example, "*-02~03" means "the third last day
          in February," and "Mon *-05~07/1" means "the last Monday in
          May."

          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.

          Timezone can be specified as the literal string "UTC", 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).

          The following special expressions may be used as shorthands
          for longer normalized forms:

                  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

          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

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     SYSTEMD.TIME(7)                                   SYSTEMD.TIME(7)

                     12,14,13,12:20,10,30 → *-*-* 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
                                    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..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
                  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

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

          Use the calendar command of systemd-analyze(1) to validate
          and normalize calendar time specifications for testing
          purposes. The tool also calculates when a specified calendar
          event would occur next.

     SEE ALSO
          systemd(1), journalctl(1), systemd.timer(5),
          systemd.unit(5), systemd.directives(7), systemd-analyze(1)

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