Principal Warwick Moyle said the initiative was set up four years ago and is designed to represent the school's cornerstone values.
"The tasks are meant to challenge the pupils and are tailored for each year group. They have to do a certain number of tasks each year, which range from creative tasks to physical and social service tasks."
Mr Moyle said pupils often asked him if they could sell goods for charity.
"I decided it was a good idea to hold a market once a year so the pupils could sell their wares on the one day.
"This is the second year we have been running the market and it's been a real hit with the pupils."
"They [pupils] decided which charities they wanted to donate to and at the end of the day we collect the money raised and write out cheques, which the pupils can then deliver."
Mr Moyle said pupils were "always keen to do the market day".
"They get a lot of pleasure out of helping others and doing their bit to make the world a bit better."