Wimbledon's chief executive has defended the schedule after Novak Djokovic was critical about matches finishing late on the show courts.

The defending champion's fourth-round match against Tim van Rijthoven on Sunday did not start until 8pm after the day's start of play was pushed back due to Centre Court's centenary celebrations at 1.30pm.

The top seed wrapped up a four-set victory over the Dutch wild card with just 21 minutes to spare before Wimbledon's 11pm curfew.

Afterwards, the 35-year-old claimed those who play the late matches are playing an "indoor tournament" with contests regularly finishing under the roof, and "most of the players would probably agree that we would all want the start of the match on Centre Court pushed earlier".

Addressing the comments on Monday, the All England Club's chief executive Sally Bolton defended Wimbledon's scheduling.

"The reality of running a tennis event is that once you start the day, you have no idea when the day is going to finish," she said.

"Matches are long, short - it's pretty unpredictable and when we look at the scheduling we think as much as we can about what the day is going to look like, but ultimately once the players walk on to court we don't have any control over how long matches run for.

"So yes, we have seen some matches go late this year and we think about that in the scheduling process, but we are certainly not moving to night sessions and we are not seeking to have players playing late.

"Other grand slams, they are playing far later into the evening - it's not a particularly unusual occurrence for players at grand slams."

Since last year, matches on Centre Court have started at a later time of 1.30pm, 30 minutes after play begins on Court One, and there has been a 20-minute break between matches.

Bolton said: "The start time has not been pushed back significantly - it's effectively half an hour."

Her comments come after Djokovic pointedly thanked the crowd and fellow six-time singles champion Billie Jean King for seeing the match through on Sunday.

"Thanks for staying for this late finish to watch tennis. Thank you Billie Jean for staying, I know it's been a long day," he said.

"I don't know if there was a curfew. There is? Phew! I am lucky, thank God.

"I remember playing a match over two days with (Rafael) Nadal a few years ago, in the semi-final. It's never very pleasant."