For 3-4-3 or 3-5-2 hours you can set in Auto or Customize mode.
In Auto mode set 3 auto settings.
In Customize mode set in three segments.
First 3 hours: gentle start to simulate morning light, 30%-40%.
Middle 4 hours: stong light for plant growth, 60%-80%.
Last 3 hours: simulate evening light, reducing stress, 20%-30%.
Or you can just use the sunrise/sunset fuction.