Identify effective timestamp for assignment data updates

Summary

How to identify effective timestamp for assignment data updates

Content

Hello Experts,

We have a requirement to identify the department, manager, business unit, etc at a particular point in time.

For e.g
-Dept is ABC at 9:00 AM
-Event 1 occurs at 10:00 AM
-Dept is updated to PQR at 11:00 AM
-Event 2 occurs at 12:00 PM
-Dept is updated to XYZ at 1:00 PM
-Event 3 occurs
-Report executed at 2:00 PM

Per our reporting requirement, when the report is run at 2:00 PM, 
- The department should show ABC for event 1
- The department should show PQR for event 2
- The department should show XYZ for event 3