old_contents: const mongoose = require('mongoose');
  const Contest = require('../models/Contest');
  
  mongoose.Promise = global.Promise;
  
  (async () => {
  	await mongoose.connect('mongodb://localhost:27017/esolang-battle');
  
  	const contest = await Contest.findOne({id: 'hackathon2018'});
  
  	contest.name = 'DIY Language Contest 2018';
  	contest.start = new Date('2018-09-23T13:00:00+0900');
  	contest.end = new Date('2018-09-23T19:00:00+0900');
  
  	await contest.save();
  
  	mongoose.connection.close();
  })();
  
new_contents: const mongoose = require('mongoose');
  const Contest = require('../models/Contest');
  
  mongoose.Promise = global.Promise;
  
  (async () => {
  	await mongoose.connect('mongodb://localhost:27017/esolang-battle');
  
  	const contest = await Contest.findOne({id: 'hackathon2018'});
  
  	contest.name = 'DIY Language Contest 2018';
  	contest.start = new Date('2018-09-23T13:00:00+0900');
  	contest.end = new Date('2018-09-23T21:00:00+0900');
  
  	await contest.save();
  
  	mongoose.connection.close();
  })();
  
subject: Extend end