By Zjan Shirinian

The first Rio 2016 test event is being held this week, with more than 300 sailors competing in the Aquece Rio International Sailing Regatta ©Getty ImagesA draft calendar of 45 test events that will be held in Rio de Janeiro ahead of the 2016 Olympic and Paralympic Games has been published as the city prepares to celebrate the two-years-to-go countdown.

With the first test event taking place this week on the waters of Guanabara Bay, on which more than 300 sailors are competing, a full timetable has for the first time been made public.

The test events are crucial to preparations for the Games, as organisers try out and put stress on every element to identify problems ahead of the real thing.

Almost 8,400 athletes, including more than 1,200 Paralympic athletes, are expected to compete in the test events.

The Aquece Rio, translated as Warm up Rio, series, has been split into three clusters beginning with July to October 2015.

Many of the outdoor events will be held during this period so they can be tested in conditions likely to be seen for the Olympic Games, which begin on August 5 2016, and Paralympic Games, which start on September 7.

The marathon test event will be held in July 2015, with rowing, equestrian, road cycling, sailing and open water swimming among the sports being staged in August.

Canoe sprint, triathlon and archery competition has been pencilled in for September, with BMX, volleyball and mountain biking the following month.

The João Havelange Stadium will stage the final test event for athletics on May 16 ©AFP/Getty ImagesThe João Havelange Stadium will stage the final test event for athletics on May 16 ©AFP/Getty Images

The second cluster of events, from November 2015 to February 2016, will focus on indoor events including table tennis, boxing and wheelchair rugby.

Large events such as athletics and swimming will form the final cluster, between March and May 2016, with organisers planning to "test and refine operations with the majority of the Games-time workforce".

Athletics will be held at the João Havelange Stadium on May 16 2016, the last day of test events, alongside swimming at the Olympic Aquatics Stadium.

"Establishing the calendar is an important step as these events will allow us to test all aspects of the competitions and ensure that, come Games time, everything will be in place for the athletes to produce their best performances," said Agberto Guimarães, Rio 2016's executive director of sport and Paralympic integration.

In total, the Rio 2016 test event programme will include 33 events for Olympic sports, six for Paralympic events and six for both Olympic and Paralympic competitions.

There will also be events organised by International and National Sports Federations, in which Rio 2016 will test specific operations.

The Rio 2016 Organising Committee said it has worked closely with International Sports Federations to put together the draft calendar

Some of the events will be ticketed.

Despite concerns about whether the under-construction Olympic golf course will be able to hold a test event a year before the Games, it has been pencilled in for August 2015 ©AFP/Getty ImagesDespite concerns about whether the under-construction Olympic golf course will be able to hold a test event a year before the Games, it has been pencilled in for August 2015 ©AFP/Getty Images

Delphine Moulin, Rio 2016's test events general manager, said: "Test events are a vital part of the preparations for staging the Games, providing the opportunity to put all our planning into practice.

"They also present an invaluable chance to integrate the Organising Committee's team with the International and National Sports Federations and Government teams, who also have an crucial role to play in the delivery of the Games."

The timetable is subject to change and specific dates will be released towards the end of this year.

This week's sailing competition is taking place amid concern over pollution levels on the course, after it was revealed last November that Guanabara Bay has 78-times Brazil's legally allowed limit of fecal pollution, and 195-times the United States limit.

Concerns have also been raised about the golf course being built for the Olympics being ready in time for a test event a year before the Games.

Despite these concerns, it has been pencilled in for August 15.

The International Tennis Federation had wanted the tennis test event to be held in August 2015, but as vice-president Juan Margets revealed in June, it will instead be held in December of that year.

Click here to see the full draft calendar.

Tomorrow marks two years until the Opening Ceremony of the Rio 2016 Olympic Games.