It doesnt matter when you apply it, make the regimen work for you, not you working for the regimen!
Everyone is different, I personally dont use minoxidil in the morning, purely because its too much hassle before work, I wash my hair at night, and use minoxidil then spironolactone after that.. and thats all.
Occasionaly on the weekends I may apply minoxidil in the morning also.
I am seeing positive results.