run job

[hangyu]

If I have a cron job that is scheduled for the 31st of the month and the
month we are in doesn't have 31 days would it be run on the last day of
the month or not run at all? thx

[Vibhor Kumar Agarwal · Accepted solution]

Depends:

If you are counting days then it will run of 1st of next month.

If you are using some sort of dating mechanish like 31st then it won't run.

[Alessandro Pilati]

Hangyu,
to avoid problems, I may suggest you to do this modification to your crontab file:

31 1,3,5,7,8,10,12
30 4,6,9,11
28 2

So you will have your job surely executed the last of the month.

Regards,
Alex

[Yogeeraj_1]

hi,

It will not run. You must modify your crontab and script accordingly.

regards
yogeeraj

[Bill Hassell]

Since each month may have a different number of days, you have to first define the rule: Is the job supposed to run on the 31st only if there are 31 days? Or is the program supposed to run on the last day of the month?

For the first answer (31st only), your job will never run on months with 30, 29 or 28 days. cron will provide exactly what you need.

If however the job is to run on the last day of the month, there is no scheduling option in cron for this. The simplest solution is to run the job on the 1st day of the month (if possible), or change the job to test for the last day of the month. There are a number of ways to do this, perhaps by running the job on the 28,29,30,31 and having the job determine whether the current date is the last day of the month.