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Job Scheduling in the Cronjob


Job Scheduling in the Cronjob 

Job Scheduling in the Cronjob  nnCron make active use of cron format in both classic and extended modes.

There are typically two formats:

 1) Traditional (inherited from Unix) cron format consists of five fields separated by white spaces:
<Minute> <Hour> <Day_of_the_Month> <Month_of_the_Year> <Day_of_the_Week>

Ex: 0 15 9 31 * ?

2) nnCron can use both traditional and "enhanced" version of cron format, which has an additional (6th) field: <Year>:

<Minute> <Hour> <Day_of_the_Month> <Month_of_the_Year> <Day_of_the_Week> <Year>

A user can select the format he would like to use by selecting or unselecting the Year field checkbox on General tab in Options dialog (which can be opened by doublecliking the nnCron icon in system tray). By default, nnCron uses the enhanced format.
The following graph shows what it consists of:
* * * * * *
| | | | | | 
| | | | | +-- Year              (range: 1900-3000)
| | | | +---- Day of the Week   (range: 1-7, 1 standing for Monday)
| | | +------ Month of the Year (range: 1-12)
| | +-------- Day of the Month  (range: 1-31)
| +---------- Hour              (range: 0-23)
+------------ Minute            (range: 0-59)
Any of these 6 fields may be an asterisk (*). This would mean the entire range of possible values, i.e. each minute, each hour, etc. In the first four fields, nnCron users can also use "nonstandard" character ? (question mark), 


More details at:
http://www.nncron.ru/help/EN/working/cron-format.htm
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