Every few years, the International Earth Rotation and Reference Systems Service calls for an adjustment, usually by one second, to be made between atomic and Earth time to compensate for deviations in the earth’s rotation. The most recent one took place over the weekend at 30 June 2012 at 23:59:60 UTC (Coordinated Universal Time).
Apparently, the change in time was not adjusted for correctly by some web servers leading to temporary problems with Qantas Airlines, Mozilla, Reddit, Gawker, LinkedIn, FourSquare, Yelp and other websites, according to the Guardian newspaper. Qantas's check-in, reservations, and plane loading systems were all forced onto manual operation for about two hours yesterday. The problem was actually with the Amadeus airline reservation system; the airline Virgin Australia was also affected, though not as severely.
Also every few years, a derecho or "a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms," hits parts of the U.S. East coast. On Friday night, a “super” derecho swept through the mid-Atlantic area between 0800 and 1100 pm causing wide spread power outages in its wake (there is a fascinating time-lapsed YouTube video of the derecho here). The storm (which felt like being in a short-lived hurricane) took out power to the Amazon’s Elastic Compute Cloud (EC2) in Northern Virginia; back-up power also for some reason did not kick in. As a result, several popular websites including Instagram, Netflix, and Pinterest experienced problems.
The storm also disrupted 911 service in Prince William, Fairfax, Stafford, Manassas, and Manassas Park counties in Northern Virginia; many Verizon and Sprint customer phones were not working in the area as well. So if you have been having trouble reaching someone either by email or by phone in the Washington, D.C. region, don’t be surprised. Things should be back to normal by Saturday.