This is just incorrect. I mean, Date.toISOString() will do that. Plus, it's very likely that this is just what's written in the post by the author and may have

This is just incorrect. I mean, Date.toISOString() will do that. Plus, it's very likely that this is just what's written in the post by the author and may have nothing to do with JavaScript. Or it could be JS that converts times to local time (I'm in PDT, so I can't tell), which is what a lot of sites do.