Twitter kicks Android app users out for five hours due to 2015 date bug

Android App Screen

If you’re worried about how your New Year’s Eve will go, don’t. It’s not even 2015 yet, and Twitter’s already had a worse one than you.

The service was down for many users over five and a half hours on Monday morning UK time, between midnight and 5am (7pm to midnight ET, and 4pm to 9pm PT), after a bug in a line of code caused the service to think that it was 29 December, 2015.

That bug caused users of the network’s Android app and mobile website to be logged out, without any ability to log back in until it was fixed at 5.25am. It also led a number of visual flaws, such as showing TweetDeck users that tweets were posted 365 days ago.

How did it happen? Well, while today may be in the dying days of 2014, according to international standards, this week is the first of 2015. When a piece of software asks which year it is, the developer has to specify what they actually mean: do they mean the year that we are in today, or the year that this week is in?

The difference one letter makes…
The difference one letter makes… Photograph: screenshot

Each of those is represented by just one character in many coding languages, and the wrong one comes first alphabetically. Assuming that this is the error that brought Twitter down overnight, it’s easy to see how it happened.

If the outage was caused by the date bug, it will also put fears to rest that Twitter had followed a long list of other companies in being hacked this holiday season. At least one Twitter user, @KingEbola, was claiming credit for the outage while it was ongoing:

But the screenshot posted by @KingEbola seems to be dated to May 2012, and now that the service is back up, their account has been wiped of all but a single tweet.

Hopefully the real New Year’s Eve will be more pain-free for Twitter, especially considering it’s usually one of the biggest nights of the year worldwide. In Japan in particular, where users tend to race to send “Happy New Year” tweets on the dot of midnight, the tweets per second reach dizzying highs – so high, in fact, that in 2012, the service was brought down by the volume.

Powered by Guardian.co.ukThis article was written by Alex Hern, for theguardian.com on Monday 29th December 2014 16.14 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010