"But it's a Bronze Age tradition, Dean," Sam protested.
Dean just looked at him. "Chinatown parades are a Bronze Age tradition."
"Well, the calendar dates to the Bronze Age, a true lunisolar calendar. The only other one still in use is the Jewish calendar, and," Sam broke off to cough into a fist.
"And you're already sick, and it's like ten degrees out tonight, and there's going to be freaking fireworks everywhere and people setting shit on fire."
"Come on, Dean, Chinese New Year only comes once a year. And when was the last time we were anywhere near a Chinese community big enough to celebrate it?"
Dean sighed. Sam wasn't really sick, just had a bit of a cold, but his lungs were fairly pissed off. Still, it was the first time in weeks he'd heard his brother's geeky babble.
"If we're going to do this, you're going to wear long johns."
Ten minutes later, Sam was bundled in about six different layers, carefully winding a scarf around his neck and over his mouth to block the cold air. Dean nodded approvingly as he zipped up his own coat.
The parade route was just a few blocks from the hotel, but by the time they reached it, Dean was already doubting the wisdom of this little trip. The streets were so packed they could barely shoulder their way through the crowds, and it seemed every third person was smoking. The reek of cigarettes filled the streets and set Sam to coughing harder than before.
Still, they got there without Sam going into asphyxia, so Dean was counting it a win. They shuffled through piles of dingy grey snow, chilling their feet straight through the boots, until they finally reached Canal Street.
The first thing that happened after they reached it was that Dean hit the deck. A loud explosion had gone off just a few feet from where they were standing, and Sam… Sam was just standing there, coughing into his scarf. And… watching the fireworks. Which Dean had just ducked away from like a shellshocked moron.
With his coat now damp and muddy, Dean stood back up, trying to regain a little dignity. "Fireworks are an important part of the celebration," Sam pointed out hoarsely. His face was half-covered, but Dean could see the laughter in his eyes. "The Chinese invented them, after all. And look on the bright side, with that much rock salt on your pants, you should be safe from spirits."
Dean glared, but he couldn't hold the expression for long. He was wearing enough layers that the slush hadn't soaked through, and Sam's smiles were rare enough these days he couldn't let one go to waste.
"So tell me more about the Bronze Age. Like, is that why the holiday moves around?"
"It's a lunisolar calendar. Really ancient. The earliest civilizations in the Yellow River Valley were way before the discovery of iron, or the ability to count the exact number of days in a solar year, so the new year comes with a new moon. Just like the Jewish calendar. Most years are twelve moons long, but seven years…"
Dean let Sam's voice fade into the background, against the babble of foreign tongues. Between the cigarettes and the fireworks and the cold air, Sam would pay for this later. But it might just be worth it.