<span>Is never safe, regardless of ability. There are many variables that can occur while swimming anywhere. If swimming outside, a person has no control over environment shifts that could lead to hazardous occurrences in the water. There are also internal changes to the body that the person might not be able to control, such as sudden cramps or loss of hydration.</span>
Well whatever time your comfortable with that is under 10pm you should be fine as long as you wake close to the same time you went to bed, like if you went to bed at 9:30pm, try to wake up at 8:50am, you'll feel more awake.
