That is completely up to you. Philips EnergyLight is made to give you daylight and energy in a way that comfortably fits into your daily routine.
It’s best to use the EnergyLight in the morning, although the afternoon or evening until 8 p.m. is also fine. If you use the EnergyLight after 8 p.m., it may effect your sleep.
Make the EnergyLight part of your daily routine
Take a light bath while having breakfast or reading the morning paper, for instance. In the office, you can switch on the EnergyLight while you work. You may interrupt your light bath and continue it later on the same day if this suits your schedule better.