"Shooting stars" ("falling stars", "meteors") may be seen from any place on earth, on any night of the year
when the sky is clear and dark, if one has the patience to watch and wait.
The best answer to the question is: "Every day."
It happens randomly
At night, when you see a shooting star, tap your main charecter, he/she will bow. The next day, you get a letter from the shooting star giving you what you wished for.
Shooting stars occur every day. It is impossible to predict when the next one will be visible in any given location.
There are thousands of them every day. The best time to see them is between about 3 AM and dawn.
Shooting stars come around 30 times each night. Make sure you don't have any tools equipped, and when you see a shooting star, press A. Your character will make a wish. If you miss the first star you see, get ready cause the shooting stars come in groups. Next day in the mail you will get a furniture item attached to a letter from a mysterious "Wishy the Star".
People started shooting each other (jizzing each other)
St. Valentine's Day Massacre: Feb. 14, 1929.
December 15, 2012, approximately 9:30 a.m.
Any day. Actually, shooting stars are happening around the world 24/7. However they won't really show up in certain areas. Too bright usually
The answer: Walk of Fame
At least once a night. Make sure you don't have anything equiped because when you see the shooting star press a few times. The next day there should be a letter from Wishy the star.
On a clear night even with a few clouds, make sure you have nothing in your hands and don't be beside a tree. Keep an eye on the sky and when a shooting star flies by press A and in the morning you will get a letter with a gift!