man/systemd.time.7

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   2 .TH "SYSTEMD\&.TIME" "7" "" "systemd 220" "systemd.time"
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  20 .\" * MAIN CONTENT STARTS HERE *
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  22 .SH "NAME"
  23 systemd.time \- Time and date specifications
  24 .SH "DESCRIPTION"
  25 .PP
  26 In systemd, timestamps, time spans, and calendar events are displayed and may be specified in closely related syntaxes\&.
  27 .SH "DISPLAYING TIME SPANS"
  28 .PP
  29 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\&.
  30 .sp
  31 .if n \{\
  32 .RS 4
  33 .\}
  34 .nf
  35 2h 30min
  36 .fi
  37 .if n \{\
  38 .RE
  39 .\}
  40 .PP
  41 All specified time values are meant to be added up\&. The above hence refers to 150 minutes\&.
  42 .SH "PARSING TIME SPANS"
  43 .PP
  44 When parsing, systemd will accept the same time span syntax\&. Separating spaces may be omitted\&. The following time units are understood:
  45 .sp
  46 .RS 4
  47 .ie n \{\
  48 \h'-04'\(bu\h'+03'\c
  49 .\}
  50 .el \{\
  51 .sp -1
  52 .IP \(bu 2.3
  53 .\}
  54 usec, us
  55 .RE
  56 .sp
  57 .RS 4
  58 .ie n \{\
  59 \h'-04'\(bu\h'+03'\c
  60 .\}
  61 .el \{\
  62 .sp -1
  63 .IP \(bu 2.3
  64 .\}
  65 msec, ms
  66 .RE
  67 .sp
  68 .RS 4
  69 .ie n \{\
  70 \h'-04'\(bu\h'+03'\c
  71 .\}
  72 .el \{\
  73 .sp -1
  74 .IP \(bu 2.3
  75 .\}
  76 seconds, second, sec, s
  77 .RE
  78 .sp
  79 .RS 4
  80 .ie n \{\
  81 \h'-04'\(bu\h'+03'\c
  82 .\}
  83 .el \{\
  84 .sp -1
  85 .IP \(bu 2.3
  86 .\}
  87 minutes, minute, min, m
  88 .RE
  89 .sp
  90 .RS 4
  91 .ie n \{\
  92 \h'-04'\(bu\h'+03'\c
  93 .\}
  94 .el \{\
  95 .sp -1
  96 .IP \(bu 2.3
  97 .\}
  98 hours, hour, hr, h
  99 .RE
 100 .sp
 101 .RS 4
 102 .ie n \{\
 103 \h'-04'\(bu\h'+03'\c
 104 .\}
 105 .el \{\
 106 .sp -1
 107 .IP \(bu 2.3
 108 .\}
 109 days, day, d
 110 .RE
 111 .sp
 112 .RS 4
 113 .ie n \{\
 114 \h'-04'\(bu\h'+03'\c
 115 .\}
 116 .el \{\
 117 .sp -1
 118 .IP \(bu 2.3
 119 .\}
 120 weeks, week, w
 121 .RE
 122 .sp
 123 .RS 4
 124 .ie n \{\
 125 \h'-04'\(bu\h'+03'\c
 126 .\}
 127 .el \{\
 128 .sp -1
 129 .IP \(bu 2.3
 130 .\}
 131 months, month
 132 .RE
 133 .sp
 134 .RS 4
 135 .ie n \{\
 136 \h'-04'\(bu\h'+03'\c
 137 .\}
 138 .el \{\
 139 .sp -1
 140 .IP \(bu 2.3
 141 .\}
 142 years, year, y
 143 .RE
 144 .PP
 145 If no time unit is specified, generally seconds are assumed, but some exceptions exist and are marked as such\&. In a few cases
 146 "ns",
 147 "nsec"
 148 is accepted too, where the granularity of the time span allows for this\&.
 149 .PP
 150 Examples for valid time span specifications:
 151 .sp
 152 .if n \{\
 153 .RS 4
 154 .\}
 155 .nf
 156 2 h
 157 2hours
 158 48hr
 159 1y 12month
 160 55s500ms
 161 300ms20s 5day
 162 .fi
 163 .if n \{\
 164 .RE
 165 .\}
 166 .SH "DISPLAYING TIMESTAMPS"
 167 .PP
 168 Timestamps refer to specific, unique points in time\&. On display, systemd will format these in the local timezone as follows:
 169 .sp
 170 .if n \{\
 171 .RS 4
 172 .\}
 173 .nf
 174 Fri 2012\-11\-23 23:02:15 CET
 175 .fi
 176 .if n \{\
 177 .RE
 178 .\}
 179 .PP
 180 The weekday is printed according to the locale choice of the user\&.
 181 .SH "PARSING TIMESTAMPS"
 182 .PP
 183 When parsing systemd will accept a similar timestamp syntax, but excluding any timezone specification (this limitation might be removed eventually)\&. 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, resp\&., 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)\&.
 184 .PP
 185 A timestamp is considered invalid if a weekday is specified and the date does not actually match the specified day of the week\&.
 186 .PP
 187 When parsing, systemd will also accept a few special placeholders instead of timestamps:
 188 "now"
 189 may be used to refer to the current time (or of the invocation of the command that is currently executed)\&.
 190 "today",
 191 "yesterday",
 192 "tomorrow"
 193 refer to 00:00:00 of the current day, the day before or the next day, respectively\&.
 194 .PP
 195 When parsing, systemd will also accept relative time specifications\&. A time span (see above) that is prefixed with
 196 "+"
 197 is evaluated to the current time plus the specified time span\&. Correspondingly, a time span that is prefixed with
 198 "\-"
 199 is evaluated to the current time minus the specified time span\&. Instead of prefixing the time span with
 200 "+"
 201 or
 202 "\-", it may also be suffixed with a space and the word
 203 "left"
 204 or
 205 "ago"\&.
 206 .PP
 207 Finally, a timespan prefixed with
 208 "@"
 209 is evaluated relative to the UNIX time epoch 1st Jan, 1970, 00:00\&.
 210 .PP
 211 Examples for valid timestamps and their normalized form (assuming the current time was 2012\-11\-23 18:15:22):
 212 .sp
 213 .if n \{\
 214 .RS 4
 215 .\}
 216 .nf
 217 Fri 2012\-11\-23 11:12:13 → Fri 2012\-11\-23 11:12:13
 218     2012\-11\-23 11:12:13 → Fri 2012\-11\-23 11:12:13
 219        2012\-11\-23 → Fri 2012\-11\-23 00:00:00
 220          12\-11\-23 → Fri 2012\-11\-23 00:00:00
 221          11:12:13 → Fri 2012\-11\-23 11:12:13
 222       11:12 → Fri 2012\-11\-23 11:12:00
 223         now → Fri 2012\-11\-23 18:15:22
 224       today → Fri 2012\-11\-23 00:00:00
 225         yesterday → Fri 2012\-11\-22 00:00:00
 226          tomorrow → Fri 2012\-11\-24 00:00:00
 227          +3h30min → Fri 2012\-11\-23 21:45:22
 228         \-5s → Fri 2012\-11\-23 18:15:17
 229         11min ago → Fri 2012\-11\-23 18:04:22
 230       @1395716396 → Tue 2014\-03\-25 03:59:56
 231 .fi
 232 .if n \{\
 233 .RE
 234 .\}
 235 .PP
 236 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\&.
 237 .PP
 238 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:
 239 .PP
 240 2 months 5 days ago
 241 .PP
 242 Note that any relative timestamp will also parse correctly where a timestamp is expected\&. (see above)
 243 .SH "CALENDAR EVENTS"
 244 .PP
 245 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:
 246 .sp
 247 .if n \{\
 248 .RS 4
 249 .\}
 250 .nf
 251 Thu,Fri 2012\-*\-1,5 11:12:13
 252 .fi
 253 .if n \{\
 254 .RE
 255 .\}
 256 .PP
 257 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\&.
 258 .PP
 259 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
 260 "\-"
 261 refers to a range of continuous weekdays\&.
 262 ","
 263 and
 264 "\-"
 265 may be combined freely\&.
 266 .PP
 267 In the date and time specifications, any component may be specified as
 268 "*"
 269 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
 270 "/"
 271 and a repetition value, which indicates that the value and all values plus multiples of the repetition value are matched\&.
 272 .PP
 273 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,
 274 ":00"
 275 is assumed\&.
 276 .PP
 277 Timezone names may not be specified\&.
 278 .PP
 279 The special expressions
 280 "minutely",
 281 "hourly",
 282 "daily",
 283 "monthly",
 284 "weekly",
 285 "yearly",
 286 "quarterly",
 287 "semiannually"
 288 may be used as calendar events which refer to
 289 "*\-*\-*\ \&*:*:00",
 290 "*\-*\-*\ \&*:00:00",
 291 "*\-*\-*\ \&00:00:00",
 292 "*\-*\-01\ \&00:00:00",
 293 "Mon\ \&*\-*\-*\ \&00:00:00",
 294 "*\-01\-01\ \&00:00:00",
 295 "*\-01,04,07,10\-01 00:00:0"
 296 and
 297 "*\-01,07\-01 00:00:00"
 298 respectively\&.
 299 .PP
 300 Examples for valid timestamps and their normalized form:
 301 .sp
 302 .if n \{\
 303 .RS 4
 304 .\}
 305 .nf
 306    Sat,Thu,Mon\-Wed,Sat\-Sun → Mon\-Thu,Sat,Sun *\-*\-* 00:00:00
 307      Mon,Sun 12\-*\-* 2,1:23 → Mon,Sun 2012\-*\-* 01,02:23:00
 308        Wed *\-1 → Wed *\-*\-01 00:00:00
 309      Wed\-Wed,Wed *\-1 → Wed *\-*\-01 00:00:00
 310     Wed, 17:48 → Wed *\-*\-* 17:48:00
 311 Wed\-Sat,Tue 12\-10\-15 1:2:3 → Tue\-Sat 2012\-10\-15 01:02:03
 312          *\-*\-7 0:0:0 → *\-*\-07 00:00:00
 313          10\-15 → *\-10\-15 00:00:00
 314        monday *\-12\-* 17:00 → Mon *\-12\-* 17:00:00
 315  Mon,Fri *\-*\-3,1,2 *:30:45 → Mon,Fri *\-*\-01,02,03 *:30:45
 316       12,14,13,12:20,10,30 → *\-*\-* 12,13,14:10,20,30:00
 317  mon,fri *\-1/2\-1,3 *:30:45 → Mon,Fri *\-01/2\-01,03 *:30:45
 318       03\-05 08:05:40 → *\-03\-05 08:05:40
 319       08:05:40 → *\-*\-* 08:05:40
 320          05:40 → *\-*\-* 05:40:00
 321     Sat,Sun 12\-05 08:05:40 → Sat,Sun *\-12\-05 08:05:40
 322     Sat,Sun 08:05:40 → Sat,Sun *\-*\-* 08:05:40
 323     2003\-03\-05 05:40 → 2003\-03\-05 05:40:00
 324     2003\-03\-05 → 2003\-03\-05 00:00:00
 325          03\-05 → *\-03\-05 00:00:00
 326         hourly → *\-*\-* *:00:00
 327          daily → *\-*\-* 00:00:00
 328        monthly → *\-*\-01 00:00:00
 329         weekly → Mon *\-*\-* 00:00:00
 330         yearly → *\-01\-01 00:00:00
 331       annually → *\-01\-01 00:00:00
 332          *:2/3 → *\-*\-* *:02/3:00
 333 .fi
 334 .if n \{\
 335 .RE
 336 .\}
 337 .PP
 338 Calendar events are used by timer units, see
 339 \fBsystemd.timer\fR(5)
 340 for details\&.
 341 .SH "SEE ALSO"
 342 .PP
 343 \fBsystemd\fR(1),
 344 \fBjournalctl\fR(1),
 345 \fBsystemd.timer\fR(5),
 346 \fBsystemd.unit\fR(5),
 347 \fBsystemd.directives\fR(7)