A magical mystery of sorts.

For those of you who are not from Michigan, you should know that we have two holidays that most other states do not celebrate. In fact, these holidays are celebrated by thousands and thousands of people. Perhaps as many as a million or more each year take time off of thier jobs to attend the rituals associated with these holidays.
And these holidays inspire retailers who have joined in with new and exciting outfits and accesories to accompany the holidays. Some stores dedicate enitre departments of thier store strictly in support of this festive season. Other than Christmas no other holiday compares to the excitement nor the dollars spent.
October 1st and November 16th are days that are etched into the brains of Michiganders forever as well of those who have been in this state during our holiday season.
Interstates are clogged with processions of trucks, suvs and cars. Campers and motor homes join in as well.
Children are taught at a very young age about the rules of the celebration and must pass a test in order to participate. As you can tell these two holidays are taken very seriously here.
Construction companies, factories, and schools all take the holidays into consideration in the planning of attendence and schedules.
The celebrations are conducted outdoors during the daylight with nightime reserved for the retelling of each attendee's experience with great detail. No incident is too small not to be relived and retold time and time again upon each person they would come into contact with.

What two holidays would give such tremendous pleasure to so many that is not associated with a religous happening? What could possibly come so close to a religous experience for so many?
There is a magic in the mystery. Can you solve it? If your from Michigan. No fair giving it away!