OzCLO 2021 dates

The first round will be held online on Wednesday, March 3, 2021. The competition is held at the same time across Australia – the specific times for each state timezone are listed in the table below.

StatePreparation TimeCompetition Time
ACT1:30 – 2:30pm2:30 – 4:30pm
NSW1:30 – 2:30pm2:30 – 4:30pm
NT12:00 – 1:00pm1:00 – 3:00pm
QLD12:30 – 1:30pm1:30 – 3:30pm
SA1:00 – 2:00pm2:00 – 4:00pm
VIC1:30 – 2:30pm2:30 – 4:30pm
WA10:30 – 11:30am11:30am – 1:30pm

The second round, for the top-scoring teams from the first round, will be held on Wednesday, March 24, 2021.


The first round is a two-hour contest. Students compete in teams of four. Each team enters their team’s solutions on one computer. Teachers are given access to a pdf copy of the problem set an hour before the competition begins for students, and should give each student a printed copy to work on.

For further information on the format of the competition, please check our FAQ page below.

Visit FAQ


Registration will open from Monday February 1 to Sunday February 28 2021. The cost of registration in 2021 will be $40 per team ($10 per student).

Register here