Rugby Sevens is shorter and faster event. In 1900 15-players were compete from one side. In Rugby sevens oval-shaped ball used to play by hand. Pierre de Coubertin introduced Rugby.

RIO Olympics 2016 Rugby Schedule

6 August 2016(Saturday)

Women’s Pool round matches 1-6 (7.30 PM)
Women’s Pool round matches 7-12 (12.30 AM)
7 August 2016(Sunday)

Women’s Pool round matches 13-18 (7.30 PM)
Women’s Quarterfinals and placing (9-12)
8 August 2016(Monday)

Women’s Semifinals and placing (5-12) (9 PM)
Women’s Medal Matches and Placing (5-8) (2 AM)
9 August 2016(Tuesday)

Men’s Pool round matches 1-6 (7.30 PM)
Men’s Pool round matches 7-12 (12.30 AM)
10 August 2016(Wednesday)

Men’s Pool round matches 13-18 (7.30 PM)
Men’s Quarterfinals and placing (9-12) (12.30 AM)
11 August 2016(Thursday)

Men’s Semifinals and placing (5-12) (9 PM)
Men’s Medal Matches and Placing (5-8) (2 AM)
So, this is the full RIO 2016 Olympics Rugby Schedule with Fixtures. I hope this helps.
Men’s Rugby Sevens Pools

Pool A Pool B Pool C
Fiji South Africa New Zealand
USA Australia Great Britain
Argentina France Kenya
Brazil Spain Japan
Women’s Rugby Sevens Pools

Pool A Pool B Pool C
Australia New Zealand Canada
USA France Great Britain
Fiji Spain Brazil
Colombia Kenya Japan