There is no good or bad time to practice breathwork– it depends on what you hope to get out of a breathing session.
You need to practice different breathing exercises if you want to get energised, calm your mind or prepare yourself for sleep. Therefore, depending on the technique you wish to use or the effect you want to achieve, you should practice at different times of the day.
For instance, Kapalabhati, also known as breath of fire or skull-shining breath, should be practised in the early hours of the day. If practised at night, you may have trouble sleeping as it will boost your energy. The opposite is also true – if you practice a sleep-focused breathing session in the early hours when you need to be energised, it will decrease your energy level, and you will struggle to get through the morning.
To learn more about this topic, head on to When is the Best Time for Breathing Exercises? (blog link).