Why do the days seem longer now?
(Lansing State Journal, March 29, 1995)


As it revolves around the sun, the Earth rotates on a tilted axis.  This tilt with respect to the plane of the Earth's orbit, is responsible for the change in daylight hours associated with the different seasons.

There are fewer hours of daylight in winter than in summer, and the number cycles with the seasons.  The short days and long nights of winter cycle into the long days and short nights of the summer like a pendulum.  People are most likely to notice the change in sunshine around the spring and fall equinoxes, because that is when the change in daylight hours is greatest.

In central Michigan, the number of daylight hours cycle between 8.7 in winter and 15.3 in summer.  Right now, there are about 12 hours between sunrise and sunset.  With each day around the spring equinox, there are about 3 additional minutes of daylight  and, thus, three fewer minutes of darkness. This is about 12 times the rate of change we can observe around summer and winter solstices.

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