Question

March 21, the 80th day of the year, is the spring equinox. find the number of hours of daylight in fairbanks on this day

Answer 1

According to a daylight calculator for Fairbanks, AK, sun rises at 07:40 and sun sets at 20:12, giving 12 hours and 32 minutes of daylight.

Note that it is not a mistake that daylight is not exactly 12 hours on that day due to refraction of the sun's rays at sunrise and sunset.

At Fairbanks, near equality to 12 hours occurs on March 16 with sunrise at 07:58 and sunset at 19:57.