state_trigger triggering when it shouldn't?

[steverumsby]

I have a luminance sensor I want to use to control some lights - turn them on when it gets dark & off when it gets light. Here's my simple start to building this:

@state_trigger("float(sensor.luminance_sensor_illuminance) < 300", state_hold_false=0)
def lounge50():
    light.lounge_1.turn_on(brightness=127)
    light.lounge_2.turn_on(brightness=127)

This certainly works at the end of the day as light falls, the lights turn on. But I'm also noticing that the lights are on in the morning when I get up.

The history graph of the luminance sensor is this and clearly hasn't gone above 300 in order to allow the state_trigger to trigger again, which is what the state_hold_false=0 is supposed to do I thought:

Am I misunderstanding what state_hold_false=0 does, or is pyscript triggering this function when it shouldn't?

Thanks,
Steve.