People not too keen on football (yes, there are some believe it or not!) sometimes joke that the gap between the two seasons happened yesterday. Most European leagues finish towards the end of May and recommence sometime in August. The transfer window is open until the end of August.  Players will normally jet off to the sun during June ready to start training for the new season, with managers needing to have an opportunity to try out new tactics, embed new players bought from other clubs, in an environment where victories are an encouragement but failure is not crucial, in fact it can be part of a learning curve.