At the North Pole, 0 hours of daylight occur on the winter solstice.
The North Pole is in polar night during the Northern Hemisphere's winter. Around the December solstice, the Sun remains below the horizon, so there is no true daylight even though some twilight may occur near the start or end of the season.
This darkness is caused by Earth's axial tilt. During the Northern Hemisphere winter, the North Pole is tilted away from the Sun; at the December solstice, the Sun reaches its lowest apparent position for northern observers.
The answer does not mean the North Pole is dark for only one day. Polar night there lasts for roughly six months, from around the September equinox until around the March equinox. The exact experience can include atmospheric twilight, auroras, moonlight, and stars.