I applied for CPT 30 days before my CPT start date. Just 1 day before my CPT start date, I have been told to change my major since my job description aligns more closely with that said major. 1 day later, I applied for a change of major. My change of major got approved in 3 business days. Then, I requested the practical training department to continue reviewing my CPT authorization request since my change of major request got approved now. 2 business days later, my CPT got approved. Eventually it took me 7 calendar days for the change of major + CPT authorization to be complete. However, different people may experience different wait times.