A Daylight Sensor is a redstone block in Minecraft. It functions as a "Light detector" or "solar panel" of sorts. A daylight sensor gives an analog redstone output - in early morning, the signal is only enough to light up about 5 tiles of redstone dust; at midday, it strengthens to 15 blocks. At night, the output strength is 0. Putting an opaque block above the sensor weakens the signal or reduces it to nothing, depending on the time of day and type of block.