It depends on many factors:

• how early the Sun rises. It is hard to walk in the dark (regardless of a good head lamp) but there is a special atmosphere.
• from july until mid September it’s very hot  from 11 am (38-40 C), so you should strart your day as early as possible to reach the next destination in time.
• also from july until mid September there are so many pilgrims that some of the albergues will be full by the time you get there
• It is hard to stay in bed for late when everybody around you swiches on the light, gets ready and makes noise.

Caminoteca’s advice: start your day as early as possible – otherwise use ear plugs and eye mask 🙂