Leaflet.Terminator
Overlay day and night regions on a Leaflet Earth map.
Demo: http://joergdietrich.github.io/Leaflet.Terminator/
Leaflet.Terminator extends the Polygon class. Adding the terminator to a leaflet map is as easy as
L.terminator().addTo(map)
In addition to all Polygon options, Leaflet.Terminator has a new option "resolution", which gives the step size at which the terminator points are computed. The step size is 1°/resolution, i.e. higher resolution values have smaller step sizes and more points in the polygon. The default value is 2.