Twilight is the shortest during the spring and fall. In the morning, before sunrise, daylight comes on quickly closest to the equinoxes. In the evening, after sunset, night falls quickly, as the sky fades after sunset. Equinoctial twilights can be 45 minutes in the mid-temperate latitudes of North America.
However, summer twilights are the longest of the year! In the summer, the Sun sets at a slanting angle, and crawls for a long time just below the horizon. Summer twilights can last for an hour and a half at latitude 40 degrees north, and even longer at higher latitudes. On the northern border of the USA, near latitude 49 degrees north, twilights last all night! The faint glow of dusk twilight crawls under the northern horizon at midnight, only to merge into the dawn twilight!
Make it a point to observe the length of twilight in the current season, and notice the change as the months progress. This is another way to become attuned to natural, God-given methods of reckoning the passage of time.