In New York City, “equilux” will be September 25, when both sunrise and sunset are scheduled for 6:47.
The days on which the length of day and night are exactly equal, called the equilux, occur a few days before the spring equinox and a few days after the autumn equinox.
Even on the days of equilux, the sky will be bright for some time before the first rays of the Sun hit, and remain bright for some time after it sets. This time of day is called twilight.
