Pick a date and a city to see when the sun rises and sets, and how Earth's tilt makes the answer wildly different from one latitude to another.
Day length on —, sorted longest to shortest:
The further from the equator, the bigger the swing. Equatorial cities stay near 12h all year; polar cities get 24-hour daylight or 24-hour night around the solstices.
The curve is Earth's 23.44° axial tilt in action. As Earth orbits the sun, the hemisphere tilted toward it gets longer days (summer solstice, ~June 21 in the north / ~December 21 in the south); the opposite hemisphere gets shorter days. Cities right on the equator barely move. The further from the equator you go, the bigger the seasonal swing.