According to French publication RMC Sport, FIFA are set to announce the official dates of this summer's transfer window.
As per the above outlet, transfer windows in national divisions can open up to four weeks before the end of the 2019/20 season, but any player signed during this time will not be eligible to play for their new club until the 2020/21 campaign.
Although most clubs across Europe still have around ten games each to play, this potentially means that the window will open up earlier for some, than others. For example, due to the cancellation of Ligue 1, French clubs can actively sign players from their own league right now, as their transfer window is officially active.