Pick a day in the Northern Hemisphere winter. Describe the changes in the length of?

Solar angle depends on the time of day, but qualitatively, any point north of the arctic circle gets no daylight during North Hemisphere winter. The length of daylight increases as you travel south, and the sun gets higher in the sky (more north) until you reach a lattitude 23deg south of the equator, when the sun is directly overhead. Then the sun appears to move north as you continue south, and the days continue to get longer until you reach the antarctic circle, at which point you will have 24 hours of daylight, e.g. the sun does not set, but travels in a circle overhead. During south hemisphere winter, all of this is reversed.