Your editor may be located in a different time zone than you. The time stamps in your edited document do not show this. This is why it might seem like the editor only worked on your order during the night, while it was actually daytime in the editor’s location.
Furthermore, some of our editors simply prefer to work in the evening or at night because they are more productive then or because they are working on other projects during the day.
In general, the time stamps in the document are not an indicator of editing quality.