Randomize ghost post dates for sqlite3 database

index.js

var sqlite3 = require('sqlite3').verbose();
var file = process.argv.slice(-1).pop();
var db = new sqlite3.Database(file);
var start = new Date("2016-01-01"),
    end = new Date("2016-10-20");

db.serialize(function() {
  var stmt = db.prepare("UPDATE posts SET created_at = ?, updated_at = ?, published_at = ? WHERE id = ?")
  db.each("SELECT id, created_at, updated_at, published_at FROM posts", function(err, row) {
    if (err) throw new Error(err);
    var date = randomDate(start, end, 3, 21),
        sdate = formatDate(date);
    stmt.run(sdate, sdate, sdate, row.id);
  }, function() {
    stmt.finalize();
  });
});

db.close();

function formatDate(date) {
  return date.toISOString().replace('T', ' ').replace(/\..*$/, '')
}

// adopted from http://stackoverflow.com/questions/31378526/generate-random-date-between-two-dates-and-times-in-javascript
function randomDate(start, end, startHour, endHour) {
  var date = new Date(+start + Math.random() * (end - start));
  var hour = startHour + Math.random() * (endHour - startHour) | 0;
  date.setHours(hour);
  return date;
}