If you want to export time entries from Aero, navigate to Manage > Time and select Export Times from the screen menu. You will be taken to a screen where you can choose filters for the times you want to export (You can also export time from the Time Entries by User report).
Set your filters and then click Next. You'll see a preview of the time entries you're going to export.
If everything looks right, click Export Times. Your time entries will be downloaded in a .csv file. If you don't see the time entries you want, click Change Filter to change your filter options and try again.