Initially when you click on Log Editor, you will be presented with a box to select the date you wish to edit.
WARNING: It is best practice not to have the log editor open between 11:30PM and 12:30AM.
And it is always best to close the log when done editing.
Click on the date you wish to edit and then click the green "Select" button or click the pink "Cancel" button to return to the main Production Suite screen.
The window below is the main log editor window:
You can see from the text at the top of the editor which hour in the day and which calendar day you are editing.
Date and Time
This shows which calendar day's log you are viewing and which hour from 00 (Midnight) to 23 (11PM) you are editing.
These buttons allow you to cut and paste, copy and paste, or just delete items. The Paste button is unavailable unless something has been cut or copied.