Since version 7.2.0 you can see the 'Time in Status' of an issue.
where you can see:
by Status*: how long the issue has been in each state.
by Transition*: how long the issue has been in the state of origin of the transition.
by Assignee*: how long has each user been assigned in each state.
(*All times are displayed on the 24/7 calendar)
How to open 'Time in Status' of an issue?
Just “click” on the status in any of the app's functionalities (Hierarchy Tree View, Dependency Table, Matrix, app gadgets...)
Hierarchy Tree view:
Dependency Table:
Matrix: