Can I write a cron expression that does not specify any day or month?

[Vandyck Lai Kai Yong]

Lately, I want to send automation that follow up with the customers everyday when the ticket had been inactive for 1 day or more.

I want to construct a cron expression that does not specify any Day-of-month or Day-of-week.

Source: https://support.atlassian.com/jira-software-cloud/docs/construct-cron-expressions-for-a-filter-subscription/

I just want to make sure can I write something like:

0 00 1 ? * ?

As from the examples listed in the documentation, it is only either  Day-of-month or Day-of-week is not specify but not both at the same time.

[Iago Docando · Accepted solution]

https://crontab.guru

0 0 1 * * * Launches every day at 01:00 am regardless of the day of the week/month, if that's what you're trying to do.

[Vandyck Lai Kai Yong]

This link is awesome.

Thank you and that is what I actually want to achieve but may I know why shouldn't I use "?" to place at the both attribute?

[Iago Docando]

I'm not a CRON expert and I haven't even looked up what "?" means but I know "*" means "any" so there's no need to go further than that, I guess :)

[Vandyck Lai Kai Yong]

Oh I see. Anyways, thank you @Iago Docando .