The sweatshirt also had the words "Jihad, born on September 11" emblazoned on the back when he turned up at his nursery school in the southern town of Sorgues on September 25.
The family and their supporters claim it was a harmless attempt at humour but they were charged with condoning a crime over the alleged reference to the 9/11 attacks on New York's twin towers in 2001.
Their trial, due to take place in December but adjourned until March 6, will take place in the town of Avignon.
The uncle bought the top and the mother dressed her son in it when she sent him to school that day.
Jihad's teacher alerted the authorities and a few days later the town mayor, Thierry Lagneau of the conservative UMP party, asked prosecutors to investigate.
"I condemn the attitude of the parents who shamefully took advantage of the person and the age of this child to convey a political message," Lagneau said at the time.
The prosecutor in Avignon previously told the court the family must have known the reaction the boy’s clothing would provoke.
“At some point there must be limits. They are not stupid. They understand the significance of what they are doing,” he said.
The mother and uncle of the boy, who official records show was born on September 11, 2009 and was given Jihad as his first name, were not known Islamists, prosecutors said.
The mother was astonished at the reaction to her son's top and at the proportions the affair had taken on, they added.
The uncle, Zeyad Bagour, was equally outraged the case has ended up in court. “We are accused of condoning a crime, It’s ridiculous,” he told France Info radio.
The family are supported by the local branch of the organisation Movement against Racism and for Friendship between Peoples (MRAP).
Josette Pessemesse, from the far-left Front de Gauche party, wrote an open letter to the court defending the “right to humour”. It was signed by around 50 people.
“This is the same as qualifying all Muslims as terrorists,” Pessemesse told France Info.
The pair risk a €45,000 fine and a one year prison sentence if found guilty.