Need to set a job in crontab

Question

Hi
Need to setup a job in crontab to run every 30 min from 8.00 am to 10.pm including both the timings.Any one can suggest it how that can be acheived?

Answer 1

Hi,
I have some good examples that describe how to set crontab execution times:
http://www.dba-oracle.com/t_crontab_examples.htm
Take a minute and read the basic rules. At forst it looks cryptic, but it's easy once you understand the columns:
field allowed values
minute 0-59
hour 0-23
day of month 1-31
month 1-12
day of week 0-7 (both 0 and 7 are Sunday)
user Valid OS user
command Valid command or script.
The date fields can contain a number of patterns to form complex schedules, as shown below.
* - All available values or "first-last".
3-4 - A single range representing each possible from the
start to the end of the range inclusive.
1,2,5,6 - A specific list of values.
1-3,5-8 - A specific list of ranges.
0-23/2 - Every other value in the specified range.
In Red Hat Linux, the month and day names can be used to specify these fields. The following examples show a selection of possible schedules:
30 * * * * root echo "Runs at 30 minutes past the hour."
45 6 * * * root echo "Runs at 6:45 am every day."
45 18 * * * root echo "Runs at 6:45 pm every day."
00 1 * * 0 root echo "Runs at 1:00 am every Sunday."
00 1 * * 7 root echo "Runs at 1:00 am every Sunday."
00 1 * * Sun root echo "Runs at 1:00 am every Sunday."
30 8 1 * * root echo "Runs at 8:30 am on the first day of every month."
00 0-23/2 02 07 * root echo "Runs every other hour on the 2nd of July."
Hope this helps. . .
Don Burleson
Oracle Press author