1 Answer

According to this schedule, never. 

Wimbledon is scheduled for 13 days, beginning on a Monday and ending on a Sunday. The five main events span both weeks, but the youth and invitational events are held mainly during the second week. Traditionally, there is no play on the "Middle Sunday", which is considered a rest day. However, rain has forced play on the Middle Sunday three times, in 1991, 1997 and 2004. On each of these occasions, Wimbledon staged a "People's Sunday", with unreserved seating and readily available, inexpensive tickets, allowing those with more limited means to sit on the show courts. If the tournament is not completed by the end of the second Sunday, all remaining matches are postponed until "People's Monday".