When is the best time to practice the martial arts?
Anytime of course!
But in looking to make progress in the martial arts, as always a plan or schedule is best.
One that inspires, but is not binding or self-defeating.
Start where you are.
The first thing in the martial arts is to practice every day- physical practice as the arts are physical. How much each day? Something? Strive for an hour, build more. But, if time is less due to other responsibilities, do what you can.
The aim is to do *something* every day, make some gains, but out effort.
Where you are in the moment, work over time, to build a schedule that you can keep most of the time- for some that might be in the morning, for other the evening- perhaps twice a day?
Work and build towards the best time.