If you're looking to track when a comparison was executed in dbForge Data Compare for PostgreSQL, note that there is no dedicated timestamp log for each operation.
However, there is a related setting that can help:
You can enable automatic restore point saving, which indirectly captures activity over time.
To configure this:
Go to Tools > Options.
Navigate to Environment > Documents > Restore.
Under the General section, set the interval in minutes for how often restore information should be saved.
This will periodically save the state of your work (including comparisons), allowing you to associate changes with approximate timestamps.