Day and Night Map
Where on Earth it is day and where it is night at this instant. The amber marker is the subsolar point — the one place where the Sun is directly overhead — and the curved shadow edge is the terminator.
About the terminator
At the equinoxes the terminator runs straight from pole to pole and every place on Earth gets 12 hours of light. Near the solstices it tilts, so one polar region sits in continuous daylight while the other is in continuous night. Twilight blurs the line in practice: the sky stays bright for a while after the Sun sets.