NAME
systemd.time - Time and date specificationsDESCRIPTION
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
PARSING TIME SPANS
When parsing, systemd will accept the same time span syntax. Separating spaces may be omitted. The following time units are understood:•usec, us, µs
•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 (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:
2 h 2hours 48hr 1y 12month 55s500ms 300ms20s 5day
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
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 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 11min ago → Fri 2012-11-23 18:04:22 @1395716396 → Tue 2014-03-25 03:59:56
2014-03-25 03:59:56.654563
2 months 5 days ago
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
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
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..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
SEE ALSO
systemd(1), journalctl(1), systemd.timer(5), systemd.unit(5), systemd.directives(7), systemd-analyze(1)systemd 252 |