When is morning, afternoon, evening and night exactly in the U.K.?

When does morning, afternoon, evening and night begin? 

So what are the times? 
You could say morning starts at 12.01am, but its still night, so do you class it as night? If so, when does the morning start? 

• Morning 5.00am-11.59am 

• Afternoon 12.00noon- 5.00pm 

• Evening 5.01pm- 10.00pm 

• Night 10.01pm- 4.59am