Automation Due Date - Custom date picker changes

[Danylo Borodai]

We have:
Due date (system)
Custom due date (only on view screen)

I need automation:
When issue created -> Custom due date take system due date data and add 3 weeks (15 working days or just 21 day)

For example: I created ticket with due date to March 4 2024, then custom due date has to be set via automation as March 25 2024.
How could I do that? 

[Danylo Borodai · Accepted solution]

Problem solved with smart value:
{{issue.duedate.plusBusinessDays(15)}}

[Kseniia Trushnikova]

@Danylo Borodai, and here is another way to add 3 weeks :)

{{issue.duedate.plusWeeks(3)}}

[Danylo Borodai]

Yeah I found it too but I needed to include business days only, but thank you a lot)