1. November 1st is Halloween every year, and October 31st is Halloween night.

2. Internationally, Halloween falls on November 1st every year, and October 31st is the eve of Halloween. It is generally the busiest night on October 31st. People will hold various horror-themed parties, and children will dress up as various ghosts and go door-to-door asking for candy.

3. The ancient Celts, in 500 BC, yearned for nature. In their calendar, November 1 every year is the official end of summer, the beginning of the new year, and the beginning of winter. So this day is called Samhain and all important things are celebrated on this day.