Hello!
I'll try to describe a step by step sequence.
Case 1.
1. Creating an epic with a name "A" -> seting a date start and date end. f.x. 2019/03/25 - 2019/03/31
2. Creating 2 subepics
-> for the 1st setting a date start on 2019/03/26 and date end on 2019/04/01
-> for the 2nd setting a date start on 2019/03/29 and date end on 2019/04/05
3. Our epic "A" still has dates from 2019/03/25 till 2019/03/31. Nothing has been changed.
Although, a new epic duration is supposed to be from 2019/03/26 (or 25) till 2019/04/05
Case 2
1. We still have epic "A"
2. Go to the backlog -> create a new issue with a date start on 2019/03/29 and date end on 2019/04/05
3. Link that issue with the epic "A" -> now the duration of epic "A" is supposed to has date end on 2019/04/05 -> but nothing has been changed again.
Probably, i made any mistakes.
How can i establish the relationship between the duration of the issue and the epic?
Is it possible?