The Premier League is an English professional league for association football clubs. At the top of the English football league system, it is the country's primary football competition. Contested by 20 clubs, it operates on a system of promotion and relegation with The Football League. The Premier League is a corporation in which the 20 member clubs act as shareholders. Seasons run from August to May, with teams playing 38 games each totalling 380 games in the season. Most games are played on Saturdays and Sundays, with a few games played during weekday evenings. It is sponsored by Barclays Bank and therefore officially known as the Barclays Premier League.