Halloween on October 31 grew out of the Celtic festival of Samhain and the eve of All Saints' Day. Today it means costumes, trick-or-treating and carved pumpkins; it is not a public holiday.
No. Halloween is not a federal holiday in the US, so government offices, banks and schools follow their normal schedule unless they choose otherwise.
When is Halloween 2013?
Halloween 2013 falls on Thursday, October 31.
Why does the date of Halloween change each year?
The date stays the same; only the weekday moves. A common year has 52 weeks and one day, so a fixed date moves one weekday later each year, and two after February 29.