field allowed values ----- -------------- minute 0-59 hour 0-23 day of month 1-31 month 1-12 (or names, see below) day of week 0-7 (0 or 7 is Sun, or use names)
A field may be an asterisk (*), which always stands for ``first-last''.
Ranges of numbers are allowed. Ranges are two numbers separated with a hyphen. The specified range is incluð sive. For example, 8-11 for an ``hours'' entry specifies execution at hours 8, 9, 10 and 11.
Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: ``1,2,5,9'', ``0-4,8-12''.
Step values can be used in conjunction with ranges. Folð
lowing a range with ``/ Names can also be used for the ``month'' and ``day of
week'' fields. Use the first three letters of the particð
ular day or month (case doesn't matter). Ranges or lists
of names are not allowed.
The ``sixth'' field (the rest of the line) specifies the
command to be run. The entire command portion of the
line, up to a newline or % character, will be executed by
/bin/sh or by the shell specified in the SHELL variable of
the cronfile. Percent-signs (%) in the command, unless
escaped with backslash (\), will be changed into newline
characters, and all data after the first % will be sent to
the command as standard input.
Note: The day of a command's execution can be specified by
two fields -- day of month, and day of week. If both
fields are restricted (ie, aren't *), the command will be
run when _e_i_t_h_e_r field matches the current time. For examð
ple,
``30 4 1,15 * 5'' would cause a command to be run at 4:30
am on the 1st and 15th of each month, plus every Friday.
Instead of the first five fields, one of eight special strings may appear:
string meaning
@reboot Run once, at startup.
@yearly Run once a year, "0 0 1 1 *".
@annually (same as @yearly)
@monthly Run once a month, "0 0 1 * *".
@weekly Run once a week, "0 0 * * 0".
@daily Run once a day, "0 0 * * *".
@midnight (same as @daily)
@hourly Run once an hour, "0 * * * *".
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