Fast when you see it and break your fast when you see it. If it is obscured from you, then count thirty days.
وبإسناده سمعت
صوموا لرؤيته وأفطروا لرؤيته فإن غم عليكم فعدوا ثلاثين
Its isnad is sahih, it occurred previously at 1931, and see 9814.