How to view the assigned date an issue was assigned to particular person

[Ileana Nuñez]

Want to determine how long it takes for a past assignee to move an issue from one status to another.

[Alexey Matveev]

You could have a look at the history tab of the issue and calculate the result. If you want to automate it, then you could use a plugin like Power Scripts or ScriptRunner. Or have a look at the Time in Status plugin, maybe it will solve your requirement.

https://marketplace.atlassian.com/apps/1211756/time-in-status?hosting=server&tab=overview