Approximately, what time are zawal and the last third of the night?

Night and day differ from one country to another. The zenith (zawaal) is identified by the lengthening of the shadow after it has reached its shortest point, which is the time the sun begins to descend westward. Night begins with the sunset and ends with the emergence of true dawn. The last third of the night can be calculated by dividing the number of hours between sunset and the emergence of dawn by three.