An interesting effect of the Commissioners’ Plan of 1811 is that on certain days of the year, the sunset is lined up with the east-west streets on Manhattan’s grid. The grid network in Manhattan, as defined in the plan, is set 28.9 degrees east from due north. If it had been aligned due north, the effect would be seen on the spring and autumn equinoxes, when the sun sets on the east-west line. Instead, because of Manhattan’s tilt, those now take place about three weeks before and about three weeks after June 21, the summer solstice. This interesting solar event has been termed Manhattanhenge, by Neil deGrasse Tyson, the director of the Hayden Planetarium.