The time log is where the administrator can view all time entries. An entry is usually created for every ticket reply (unless the amount of time recorded is set to zero). Access the time log by simply clicking the TIME TRACKING menu option.
The time log list looks like this:
Using the controls at the top of the list you can filter it by:
Clicking on the title column on any row will take you to the detail of that time entry:
As long as the time entry has not been processed as part of an invoice the admin will be able to update/change it.