Some locales don't pad month or day values:

dd = new Date( Date.UTC(2012, 1, 2, 3, 0, 0 ));
2012-02-02T03:00:00.000Z
console.log( dd.toLocaleString() );
2/2/2012, 12:00:00 AM`

After reading https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString a user not used to single-digit months or days might assume that all values are 2 digits long, and be surprised by errors, like for example me in Argentina.

All the values in the page are 2-digits long.