minute hour day month DayOfWeek command
minute -integers from 0 to 59
hour -integers from 0 to 23
Day-an integer from 1 to 31 (must be a valid date for the specified month)
month -an integer from 1 to 12 (or a month such as the Jan or Feb abbreviation)
DayOfWeek -integers from 0 to 7, 0 or 7 to describe Sunday (or as represented by sun or mon shorthand)
Command
-Commands to execute (commands that can be used as Ls/proc >>/tmp/proc or execute custom scripts) For each of these statements, the asterisk (*) represents all available values. For example, when referring to month, the command is executed monthly (subject to other restrictions ).
The hyphen (-) between integers denotes an integer sequence , for example 1-4 means integers 1,2,3,4
The specified value is separated by commas. Such as: 3,4,6,8 represents these four specified integers.
the symbol "/" specifies the stepping setting. "/" indicates a stepping value. such as the 0-59/2 definition is executed every two minutes. The step value can also be represented by an asterisk. such as */3 is used to run a specified task every three months running.
About the use of crontab under Linux
