It was 2007 Nottingham when 5 matches (3 quarter finals, 2 semi finals) were played indoors because of torrential rain and a backlog of matches.
On the Thursday, Karlovic won his quarter final by beating del Potro 7-6, 7-5 on the grass. None of the other quarter finals were played that day because of the torrential rain that came pouring down straight after Karlovic's win, rain which continued for the rest of Thursday and throughout the whole Friday.
As a result of this, the other 3 quarter finals and both semi finals were all played on indoor hardcourt on the Friday. Clement beat Gasquet (2005 and 2006 Nottingham champion) 6-4, 6-3, and Gasquet was annoyed afterwards, as a 2-time defending champion, that he wasn't able to play the match on grass. Bjorkman beat Mathieu 2-6, 6-3, 6-4, and Tursunov beat Garcia-Lopez 4-6, 6-3, 7-5. That was then followed later that Friday with the semi finals, Clement beating Bjorkman 6-2, 6-4, and Karlovic beating Tursunov 7-5, 6-4. On the Saturday, Karlovic won the tournament, beating Clement 3-6, 6-4, 6-4, in the final when they were back outdoors on the grass.
The following year, the 2008 Nottingham final was played on indoor hardcourt, because the Saturday was rained out. Karlovic retained his title by beating Verdasco 7-5, 6-7, 7-6.