How to schedule a Cron job for multiple days every month? - cron

I wish to schedule a airflow job for specific set of dates every month, for example 11th and last day of every month and used the below scheduler expression
25 14 11,L * * # At 2:45 pm on 11th and last day of every month
When I validated the above in https://crontab.guru/ and http://cron.schlitt.info/ i was told the expression as invalid.
Is it possible to schedule together for a known and a unknown (here last) day of every month? If not is there any other way to achieve this?

maybe your cron does not support the "L" flag. you can refer to this CRON job to run on the last day of the month

Related

Cron job one schedule for 3rd Sunday but different schedule every other day

We have jobs that are scheduled to run 1 time per day - every day
We do maintenance every 3rd Sunday of the month.
Up until now every month we have manually adjusted the cron to make the job run a little later in the morning then after maintenance we reset to the desired schedule
I am trying to change cron so that we
run at 7:00am every day EXCEPT the third Sunday of the month
run at 9:00am only on the third Sunday of the month
the second item I am able to handle
0 13 15-21 * 0
however, the first has me stumped. I thought this would do the job but it will only execute this if the day is between 1-14 or 22-31 but what if the 15th is not Sunday - then it won't run.
0 11 1-14,22-31 * *
How do I tell cron to run a schedule EXCEPT the third Sunday of the month?
There is a large base of guidance on how to limit when a cron runs to a specific window but I haven't found much for how to EXCLUDE a cron from a specific window
******** UPDATE ********
I think I may have come up with an answer - not sure if it is the most efficient but
0 11 1-14,22-31 * 0
0 13 15-21 * 0
0 11 1-14,22-31 * 1-6
The above will
run at 11:00 UTC on Sunday if date is between 1-14 or 22-31
run at 13:00 UTC on Sunday if date is between 15-21 (3rd Sunday)
run at 11:00 UTC Monday through Saturday all month
If a cron job has different timing than others, then it best to just define it by itself rather than trying to combine, unless you put some code in your script to do what you actually want. Doing something in cron on some nth day of the month is a pretty well known problem. Most crontab man pages have this note:
Note: The day of a command's execution can be specified in the following two fields — 'day of month', and 'day of week'. If both fields are restricted (i.e., do not contain the "*" character), the command will be run when either field matches the crent time. For example,
"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.
So it does OR between the day of the week and the day of the month, not an AND. I don't who ever thought this was helpful, but that's the way it is. You can see solutions at:
Run every 2nd and 4th Saturday of the month
you need something like (this assumes cron runs /bin/sh):
[ `date +\%w` -eq 6 ] && <command>
on your cron job line, the above is would restrict to running only on Saturday.

Scheduling job every other day in Azure Databricks

I need to schedule a job which will run every other day(if start is Mon then Wed, Fri, Sunday...).
But in databricks job scheduler options are only for day, week, month and yearly basis.
You just need to specify schedule as cron expression instead of using UI options. Databricks jobs are using Quartz syntax, so for your case expression will look as following (fill seconds/minutes/hours for time when you need to start jobs):
seconds minutes hours * * 1,3,5,7
The cron trigger expression consists of 6 fields separated by a space:
Seconds (0 -59)
minute (0 -59)
Hour (0 - 23)
Day of the month (1-31)
Month (1-12)
Day of the week (0-6, 0 = Sunday)
Year (optional, default is current year)
For the given schedule, the expression would be:
0 0 0 1/2 * ?
This means that the schedule will run at midnight (0th min and 0th hour) every other day (/2 in the third field). The 4th and 5th fields are not relevant so they are set to a wildcard ().
To summarize, this schedule will run every other day at 12.00 AM
I have tried the following schedule in databricks and it accepts the cron as valid schedule. you can also try the following cron along with #alex-ott's answer.
seconds minutes hours ? * 1,3,5,7
As you are specifying the day of the week, your day of the month should be ?.

cron expression every 2 days not making sense for monday

i have a cron expression-
0 0 12 */2 * ?
If start date is monday and time is 11:40 am, the next trigger date i'm expecting is monday 12:00, followed by wednesday, friday,etc.
But when i give this expression, the first trigger is set to tuesday 12:00, followed by thursday, saturday,etc
i verified this on http://cronmaker.com
Why does this behavior occur for monday?
If the start date is set to any other day it seems to behave the way its supposed to.
So if it was set on Tuesday 11:50 am , the first trigger is on tuesday 12:00.
Please help me understand. Is it a bug or expected behavior? Is there a work around to make it trigger on monday?
Thanks
Your cron schedule doesn't care about the day of the week. It is running simply on every uneven day of the month. This is the expected behaviour.
If you need it to run on Mondays, you should use something like 0 0 12 ? * MON,WED,FRI
First of all you expression only uses ? for the day of the week, so effectively you are not controlling that part.
Second the / character in a Cron expression indicates an increment. And when used next to a *, the star just means the lower bound for that value, 1 for the day of the month.
So indeed you are asking for a fire at noon every uneven day of the month. And the start time of the trigger will only constrain the first instance to be the next uneven day of the month.
You cannot express what you seem to desire with a cron trigger - that is a schedule which is based off the start time of the trigger. You should use s SimpleTrigger for this

cron expression for quartz to start on particular month and repeat every months onwards

I am working on Quartz Scheduler where need to trigger my job on basis of monthly where user can select desired month date from which he want to make it run for every month on that particular date. lets say- I want to schedule quartz job from August 20,2015 which should run every month on 20th, but it should not start by today,must be start on August 20,2015 onward. what would be the cron expression for this?
I have tried a lot to find out the matching thread but did not worked for me.
like if i have to make for every month which start on 20 May 2015 and repeat every 20th date of month the cron expression would be [0 0 12 20 1/1 ? *].for this requirement lot of things available around and works nicely. but how to schedule Quartz which must fire on particular date and repeat onward for every month on that particular date and time?
Please help me out.any link or any guideline would be appreciable.

How to run cronjob on every month first friday?

I have cronjob to be run on every month first friday evening
i used the below mentioned entry
00 20 1-7 * Fri [ "$(date '+\%a')" = "Fri" ] && $HOME/path/to/my/script.sh > /dev/null 2>&1
This entry should run my script if Friday falls withing 1-7 day of the month, but my script is getting executed even after 7th (i.e on all Fridays of the month).
Please suggest how to fix it.
This is because when you specify a day of month and day of week, cron will execute the job when EITHER of those constraints are true. From the man page for crontab (5):
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 (i.e.,
aren't *), the command will be run when either field matches the cur‐
rent time. For example,
``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.
There isn't a direct way in cron to do what you want, but cron : how to schedule to run first Sunday of every month describes a workaround by using cron to run your script e.g. every Friday and then calculating in the script if the day of month is in the range 1-7, and only continuing when that is the case.
In response to the comment about using 5 rather than Fri to specify day of week: using Fri is OK, as the man page says:
Months or days of the week can be specified by name.

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