Because a holiday is supposed to "start" at a specific date, that's what makes it a holiday and a tradition. It's just dirty commersialism to "start" Christmas in November or October. Halloween is pretty new in Sweden, at least the anglosaxon variant of it. It began to be adopted just about 10 years ago by youngsters. Before that we just put candles on relatives' graves on All Saints Day, 1st of November, nothing else.
As much as I admire American gun laws and freedom of speech I hate American commersialism and shallowness. Sorry.
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Let come what will, I'll try it on,
My condition can't be worse;
And if there's money in that box,
'Tis munny in my purse.