As approved by its World Governing Body, Football associations can open their transfer windows before the current season is finished under new temporary regulations issued by FIFA. The world governing body has also announced that players can be registered for and play for up to three clubs – rather than the usual two – during the same season. FIFA has set the parameters and offered the necessary guidance and regulatory changes, but it is down to the individual member associations to confirm their transfer window opening and closing dates.
Source: Sky Sports