Early.

First of all, it was October, a rare month for boys. Not that all months aren't rare. But there be bad and good, as the pirates say. Take September, a bad month: schoool begins. Consider August, a good month: school hasn't begun yet. July, well, July's really fine: there's no chance in the world for school. June, no doubting it, June's best of all, for the school doors spring wide and September's a billion years away.

But you take October, now. School's been on a month and you're riding easier in the reins, jogging along. You got time to think of the garbage you'll dump on old man Prickett's porch, or the hairy-ape costume you'll wear to the YMCA the last night of the month. And if it's around October twentieth and everything smoky-smelling and the sky orange and ash grey at twilight, it seems Hallowe'en will never

come in a fall of broomsticks and a soft flap of bedsheets around corners.

But one strange wild dark long year, Hallowe'en came early.

One year Hallowe'en came on October 24, three hours after midnight.

At that time, James Nightshade of 97 Oak Street was thirteen years, eleven months, twenty-three days old. Next door, William Halloway was thirteen years, eleven months and twenty-four days old. Both touched toward fourteen; it almost trembled in their hands. 

And that was the October week when they grew up overnight, and were never so young any more ...

Ray Bradbury, from Something Wicked This Way Comes