The deadline for Barton to accept or deny the charges had been 6pm tonight but the Football Association extended that to 12pm on Wednesday following a request from the Rangers captain's representatives.
The FA said in a statement: "The deadline of 6pm on Tuesday 15 May, which Joey Barton had until to respond to the two FA charges against him for alleged violent conduct has been extended to 12 noon on Wednesday 16 May following a request from his representatives.
"The charges against the Queens Park Rangers midfielder are in relation to Sunday's match against Manchester City at the Etihad Stadium.
"Following the player's dismissal in the 54th minute of the fixture, there followed two incidents involving Manchester City's Sergio Aguero and Vincent Kompany.
"As Barton had already been dismissed, both of these incidents fell outside of the jurisdiction of the referee."
Barton was set to be high on the agenda when QPR officials arranged to meet to discuss the club's summer transfer plans.
As well as mulling over whether to accept their skipper's violent conduct charges, they had also planned to debate whether to take any internal action against him.
Reports suggested they would consider trying to offload - or even sack - Barton, who has three years left to run on his contract.
The midfielder could start next season with a ban that runs into double figures for his sending-off and subsequent behaviour in QPR's final game of the season on Sunday.
Having been red carded for elbowing Carlos Tevez, Barton then kicked Sergio Aguero before attempting to headbutt Vincent Kompany as he left the field.
He will receive an automatic four-match ban for what was his second dismissal of the season, and could receive three-match suspensions for each of the violent conduct charges.
On top of that, the FA's regulatory panel will have discretionary powers to further increase the length of the suspension if charges are found to be proven.
Barton claimed on Twitter that his violent actions were a cynical ploy to provoke a City player to be sent off, something the panel may well frown upon.
Barton insisted via Twitter that he had not lost his head but that a team-mate "suggested I should try to take 1 of theirs with me".
QPR chairman Tony Fernandes said that Barton's future would be reviewed but that the 29-year-old had been an integral part of the club.
Barton also followed up his expletive-laden Twitter attack on Alan Shearer - his former manager at Newcastle and current Match of the Day pundit - last night by turning on the programme's presenter, Gary Lineker, posting: "back under your stone you odious little toad..."
Barton also accused "Mr Squeaky Clean" Lineker of having "skeletons" in his closet. Lineker hit back , saying: "He's said what he wants to say. That's fine.
"It's scurrilous nonsense. I don't know what he's thinking of.
"I've had a good look around my house and in all the closets and all I found was packets of crisps. It's pie in the sky.
"He's doing what he does and you have to live with that."
As well as the Barton issue and possible transfer targets, QPR were expected to discuss which players to keep and which to move on from their bloated squad, one which narrowly avoided an immediate return to the npower Championship.