30 years ago when light bulbs were typically 100watts and had short lives a sensor like this could save some serious power and cost of bulbs.
These days with LED bulbs that are are put out a reasonable light output using less than 10 watts I am no so sure.
When checking out a replacement sensor switch I found the switch consumes 6 watts of power (More than the bulb I was using)
A simple time switch only uses around 1 watt.
So the equation for power use could be
Sensor switch 24 hours x 6 + say 5 watts when light on = 150 watts per day
Time switch 24 hours per day x 1 + 5 watts for light on for say 10 hours = 74 watts (half the power usage)
Which way would you go?