@kwint That’s what I use it for. If your light supports transition. You can add a service call ligth.turn_on with transition time to the actions.
Add Action → Call Service → Light: turn on → Select your Target → Select Transition (set a time) → select Brightness (target brightness)
or yaml
service: light.turn_on
data:
transition: 30
brightness_step_pct: 100
target:
entity_id: light.somelight
if your light doesn’t support transition, i made this blueprint script here: Increase or decrease light brightness over time - Blueprints Exchange - Home Assistant Community (home-assistant.io)