halo.bungie.net is converting and displaying your join date according to PDT/PST and has always done that because the server-side is typically not able to know what time zone you're observing. It's always been like that. On the other hand, because bungie.next is constructed as a client-side web application (at least [i]this[/i] interface) which just consumes a web service for the data*, the client-side script (JavaScript) is able to convert your join date to a local date since it has partial access to your system date and time. To prove it, go to your profile and take note of your join date, change your time zone to Pacific time, then reload the page. It will show the same date as halo.bungie.net. *This is something few websites do with a similar interface, and I can only think of Facebook and Twitter as similar examples.