PowerStar Timer and PIR Motion Sensor Flood light possess some similarities, both have dimming features and can withstand more than 1 night of use. The main difference is that Timer requires that you manually configure when to activate a full bright light and when to switch to dim light. PIR motion sensor on the other hand defaults to use dim light and only switches to a full bright light once the presence of a person is detected.
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Under normal circumstance, PIR motion sensor is preferred, because it conserves the battery. It is also useful for security purpose as it acts as a deterrent against thieves and people with malicious intent. However, if a strict policy needs to be observed regarding the brightness, then timer would be your go-to choice.
Checkout PowerStar Solar Timer Flood Light