Hummingbird feeder question

Hey all - I have a hummingbird feeder with a heater on a timer to prevent the nectar from freezing.

if you feed hummingbirds year round in the Seattle area do you keep the heater on 24/7? Or set a timer for a few hours before sunrise?

Sorry new to this and want to take care of the hummingbirds in my area.

Edited for clarity: the last few years I have set alarms during cold snaps and put nectar out around 5am. Using the heater, I’d like to avoid getting out of bed at 5am in the cold. Does anyone use a hummingbird nectar heater and what is their routine during cold snaps?