It is a known fact that some people learn English better in the evening and some others in the morning. Some researchers believe that young people are more effective in learning English in the afternoon and evening and less effective in the morning. Some others believe vice-versa. Some new researches show that each individual has his own best learning time based on his own schedule.
As you can see there are different opinions. However, everybody agrees that you should learn English when you are rested. Learning when you are tired is not effective. So, after a good rest/sleep learning is more effective. The lack of sleep affects not only learning ability but also creativity, attention, and reaction time.
To be undisturbed when learning, is another major factor that affects your effectiveness of learning. When you are learning you don’t want to hear the traffic’s honks or your little sister coming in and out of the room all the time.
Some of my students told me that when they are learning English they are also watching TV and listening to music. Of course, I asked why. They simply said that it is English so it must be good for them. They also admitted that the learning time is considerably longer than when they are learning English without TV and music.
In conclusion, one thing can be said, learn English when you are rested/not tired and choose a quiet place where you can learn undisturbed.