It's hard work, rushing through a PPL, but I started mine (non-EASA) a fair few years ago now, on 31st Jan with a trial lesson, returning 4 days later to start the PPL proper. I flew on 16 days and did the GFT on the 7th March. So 36 days total, but only flew on week days when the weather was suitable.
You'd now have to do 5 hrs more than I did but I guess you could do it in 21 days if you were up for it and had completed the exams first so that you could concentrate on the flying. I just studied on the evenings whilst in the B&B I stayed at.