The summer transfer window gives Premier League clubs the chance to sell and purchase players ahead of the new season.
Windows were introduced as part of a compromise agreement with the European Commission about how the whole transfer system worked and how it could best preserve contractual stability for both the player and the club while allowing movement at prescribed times during the year - the summer and winter transfer windows in effect.
The summer transfer window opens soon after the Premier League season finishes and closes at 11pm BST on the final working day of August. The dates may slightly vary from year to year.
If deadline day is a weekend or a bank holiday, there is flexibility to go into the next working day, which is normally until 5pm.