How to automate the creation of subtasks based on a date field

Question

Hello! Is it possible to automate the creation of subtasks based on a date field? I.e.: if we have the field "Due date" in an issue, it is possible to open a specific subtask X days before? (the time we determine)

For example:

- Due date: October 1st

- Automatic opening of subtask: 15 days before (September 15th)

What would be the automation logic (trigger and date comparison)?

Thank you very much!

Vikrant Yadav · Answer

@Javier Peraita  It means no issues have Deadline greater than 15 days from now.

Try to create an issue with Deadline 27th Aug , then Do JQL search, issue would be visible.

Javier Peraita · Answer

@Vikrant Yadav I am doing it with the JQL code but it does not return any result. Is it possible that it is because the field is date+time ?

Vikrant Yadav · Answer

@Javier Peraita  Are you filter those issues in which Deadline is greater then 15days from now via Issue Search or JQL ?

If those issues are visible via JQL then automation also validate the query ? 
Is validate query giving zero result ?