probably
the longest and shortest day of the year
i assume you mean the longest daylight period and the shortest daylight period
these are determined by sunrise and sunset times
in the northern hemisphere, the longest day is the summer solstice, around June 20
and the shortest day is the winter solstice, around December 21.
note that in the southern hemisphere, these are reversed
this map
Where is the Sun directly overhead right now?
shows the day and night areas of earth
note that, since it is summer in the north and winter in the south,
the arctic is in day light, and the antarctic is at night
this is related to the 23 degree tilt of the earth's axis relative to the plane of its orbit about the sun
the other planets have different axis tilts
this is a good discussion
We are all familiar with how long a day is here on Earth. But how long is a day on the other planets of our Solar System?