1SYSTEMD.TIME(7) systemd.time SYSTEMD.TIME(7)
2
6 systemd.time - Time and date specifications
7
9 In systemd, timestamps, time spans, and calendar events are displayed
10 and may be specified in closely related syntaxes.
11
13 Time spans refer to time durations. On display, systemd will present
14 time spans as a space-separated series of time values each suffixed by
15 a time unit.
16 2h 30min
18 All specified time values are meant to be added up. The above hence
20 refers to 150 minutes.
21
23 When parsing, systemd will accept the same time span syntax. Separating
24 spaces may be omitted. The following time units are understood:
25 · usec, us
27 · msec, ms
29 · seconds, second, sec, s
31 · minutes, minute, min, m
33 · hours, hour, hr, h
35 · days, day, d
37 · weeks, week, w
39 · months, month
41 · years, year, y
43 If no time unit is specified, generally seconds are assumed, but some
45 exceptions exist and are marked as such. In a few cases "ns", "nsec" is
46 accepted too, where the granularity of the time span allows for this.
47 Examples for valid time span specifications:
49 2 h
51 2hours
52 48hr
53 1y 12month
54 55s500ms
55 300ms20s 5day
56
58 Timestamps refer to specific, unique points in time. On display,
59 systemd will format these in the local timezone as follows:
60 Fri 2012-11-23 23:02:15 CET
62 The weekday is printed according to the locale choice of the user.
64
66 When parsing systemd will accept a similar timestamp syntax, but
67 excluding any timezone specification (this limitation might be removed
68 eventually). The weekday specification is optional, but when the
69 weekday is specified it must either be in the abbreviated ("Wed") or
70 non-abbreviated ("Wednesday") English language form (case does not
71 matter), and is not subject to the locale choice of the user. Either
72 the date, or the time part may be omitted, in which case the current
73 date or 00:00:00, resp., is assumed. The seconds component of the time
74 may also be omitted, in which case ":00" is assumed. Year numbers may
75 be specified in full or may be abbreviated (omitting the century).
76 A timestamp is considered invalid if a weekday is specified and the
78 date does not actually match the specified day of the week.
79 When parsing, systemd will also accept a few special placeholders
81 instead of timestamps: "now" may be used to refer to the current time
82 (or of the invocation of the command that is currently executed).
83 "today", "yesterday", "tomorrow" refer to 00:00:00 of the current day,
84 the day before or the next day, respectively.
85 When parsing, systemd will also accept relative time specifications. A
87 time span (see above) that is prefixed with "+" is evaluated to the
88 current time plus the specified time span. Correspondingly, a time span
89 that is prefixed with "-" is evaluated to the current time minus the
90 specified time span. Instead of prefixing the time span with "+" or
91 "-", it may also be suffixed with a space and the word "left" or "ago".
92 Finally, a timespan prefixed with "@" is evaluated relative to the UNIX
94 time epoch 1st Jan, 1970, 00:00.
95 Examples for valid timestamps and their normalized form (assuming the
97 current time was 2012-11-23 18:15:22):
98 Fri 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
100 2012-11-23 11:12:13 → Fri 2012-11-23 11:12:13
101 2012-11-23 → Fri 2012-11-23 00:00:00
102 12-11-23 → Fri 2012-11-23 00:00:00
103 11:12:13 → Fri 2012-11-23 11:12:13
104 11:12 → Fri 2012-11-23 11:12:00
105 now → Fri 2012-11-23 18:15:22
106 today → Fri 2012-11-23 00:00:00
107 yesterday → Fri 2012-11-22 00:00:00
108 tomorrow → Fri 2012-11-24 00:00:00
109 +3h30min → Fri 2012-11-23 21:45:22
110 -5s → Fri 2012-11-23 18:15:17
111 11min ago → Fri 2012-11-23 18:04:22
112 @1395716396 → Tue 2014-03-25 03:59:56
113 Note that timestamps printed by systemd will not be parsed correctly by
115 systemd, as the timezone specification is not accepted, and printing
116 timestamps is subject to locale settings for the weekday while parsing
117 only accepts English weekday names.
118 In some cases, systemd will display a relative timestamp (relative to
120 the current time, or the time of invocation of the command) instead or
121 in addition to an absolute timestamp as described above. A relative
122 timestamp is formatted as follows:
123 2 months 5 days ago
125 Note that any relative timestamp will also parse correctly where a
127 timestamp is expected. (see above)
128
130 Calendar events may be used to refer to one or more points in time in a
131 single expression. They form a superset of the absolute timestamps
132 explained above:
133 Thu,Fri 2012-*-1,5 11:12:13
135 The above refers to 11:12:13 of the first or fifth day of any month of
137 the year 2012, but only if that day is a Thursday or Friday.
138 The weekday specification is optional. If specified, it should consist
140 of one or more English language weekday names, either in the
141 abbreviated (Wed) or non-abbreviated (Wednesday) form (case does not
142 matter), separated by commas. Specifying two weekdays separated by "-"
143 refers to a range of continuous weekdays. "," and "-" may be combined
144 freely.
145 In the date and time specifications, any component may be specified as
147 "*" in which case any value will match. Alternatively, each component
148 can be specified as a list of values separated by commas. Values may
149 also be suffixed with "/" and a repetition value, which indicates that
150 the value and all values plus multiples of the repetition value are
151 matched.
152 Either time or date specification may be omitted, in which case the
154 current day and 00:00:00 is implied, respectively. If the second
155 component is not specified, ":00" is assumed.
156 Timezone names may not be specified.
158 The special expressions "minutely", "hourly", "daily", "monthly",
160 "weekly", "yearly", "quarterly", "semiannually" may be used as calendar
161 events which refer to "*-*-* *:*:00", "*-*-* *:00:00",
162 "*-*-* 00:00:00", "*-*-01 00:00:00", "Mon *-*-* 00:00:00",
163 "*-01-01 00:00:00", "*-01,04,07,10-01 00:00:0" and "*-01,07-01
164 00:00:00" respectively.
165 Examples for valid timestamps and their normalized form:
167 Sat,Thu,Mon-Wed,Sat-Sun → Mon-Thu,Sat,Sun *-*-* 00:00:00
169 Mon,Sun 12-*-* 2,1:23 → Mon,Sun 2012-*-* 01,02:23:00
170 Wed *-1 → Wed *-*-01 00:00:00
171 Wed-Wed,Wed *-1 → Wed *-*-01 00:00:00
172 Wed, 17:48 → Wed *-*-* 17:48:00
173 Wed-Sat,Tue 12-10-15 1:2:3 → Tue-Sat 2012-10-15 01:02:03
174 *-*-7 0:0:0 → *-*-07 00:00:00
175 10-15 → *-10-15 00:00:00
176 monday *-12-* 17:00 → Mon *-12-* 17:00:00
177 Mon,Fri *-*-3,1,2 *:30:45 → Mon,Fri *-*-01,02,03 *:30:45
178 12,14,13,12:20,10,30 → *-*-* 12,13,14:10,20,30:00
179 mon,fri *-1/2-1,3 *:30:45 → Mon,Fri *-01/2-01,03 *:30:45
180 03-05 08:05:40 → *-03-05 08:05:40
181 08:05:40 → *-*-* 08:05:40
182 05:40 → *-*-* 05:40:00
183 Sat,Sun 12-05 08:05:40 → Sat,Sun *-12-05 08:05:40
184 Sat,Sun 08:05:40 → Sat,Sun *-*-* 08:05:40
185 2003-03-05 05:40 → 2003-03-05 05:40:00
186 2003-03-05 → 2003-03-05 00:00:00
187 03-05 → *-03-05 00:00:00
188 hourly → *-*-* *:00:00
189 daily → *-*-* 00:00:00
190 monthly → *-*-01 00:00:00
191 weekly → Mon *-*-* 00:00:00
192 yearly → *-01-01 00:00:00
193 annually → *-01-01 00:00:00
194 *:2/3 → *-*-* *:02/3:00
195 Calendar events are used by timer units, see systemd.timer(5) for
197 details.
198
200 systemd(1), journalctl(1), systemd.timer(5), systemd.unit(5),
201 systemd.directives(7)
202systemd 219 SYSTEMD.TIME(7)