According to Twitter's server response at the time of writing, most of 2015 has happened, and we are heading into a bright new 2016 in a couple of days time.
Querying Twitter's HTTP response headers at https://twitter.com returns a time stamp dated one year into the future: "date: Mon, 29 Dec 2015 02:09:37 UTC".
Consequently, users of Twitter's popular Tweetdeck application have experienced seeing every incoming tweet appear with a time stamp reporting the tweet to be from 365 days ago.
At the same time that Twitter's servers began returning the incorrect date, some users of Twitter's official Android app were logged out of the service, and were unable to log in again via the app. Users of some third-party Twitter applications have also reported being locked out of their apps.
"We're working on resolving issues some users are having signing in on some platforms," Twitter's support account said a couple of hours after the issues appeared.
In October, the social network reported a $175 million net loss on revenue of $361 million, which represented an increase of 114 percent year on year.
The company currently has 284 million monthly active users.
Twitter announced in November that it would begin tracking which other applications people have installed on their mobile devices in a bid to better target ads and content.
"We are collecting and occasionally updating the list of apps installed on your mobile device so we can deliver tailored content that you might be interested in," Twitter said at the time.
Twitter users can prevent their app lists from being harvested by activating the "Limit Ad Tracking" or "Opt out of interest-based ads" features on Apple or Android mobile devices, respectively.