An update to this story, providing additional information, can be found here

Reddit, Mozilla, Gawker, and possibly many other web outfits experienced brief technical problems on Saturday evening, when software underpinning their online operations choked on the "leap second" that was added to the world's atomic clocks.

On Saturday, at midnight Greenwich Mean Time, as June turned into July, the Earth's official time keepers held their clocks back by a single second in order to keep them in sync with the planet's daily rotation, and according to reports from across the web, some of the net's fundamental software platforms – including the Linux operating system and the Java application platform – were unable to cope with the extra second.

Many computing systems use what's called the Network Time Protocol, or NTP, to keep themselves in sync with the world's atomic clocks, and when an extra second is added, some just don't know how to handle it.

The "leap second bug" hit just as the web was recovering from a major outage to Amazon Web Services, an online operation that runs as much as 1 percent of the internet. Some operations, including Google, saw the leap second coming and prepared for it, but others weren't so diligent.

In a post to Twitter, Reddit – the popular news aggregation and discussion site owned by the same parent company as Wired – said it was experiencing problems with "Java/Cassandra," referring to the open source database, and it attributed these problems to the leap second. Originally designed by Facebook and now used across the web and beyond, Cassandra is built with Java.

Reddit did not immediately respond to a request for comment.

Meanwhile, Eric Ziegenhorn – a site reliability engineer with Mozilla, maker of the Firefox web browser – posted a bug report on the organization's site saying that Mozilla was experiencing problems with Hadoop, another open source platform written in Java. Ziegenhorn also blamed the leap second, since the problems had hit at midnight GMT.

Others complained of issues with Linux servers, and according to BuzzFeed, Foursquare, Yelp, LinkedIn, Gawker, and StumbleUpon were also felled by the leap second bug.

Of these five outfits, only Gawker has responded to a request for comment, saying it experienced the leap bug problem with the Java-happy Tomcat web servers it uses to serve up its site. "Our web servers running tomcat came close to zero response (we were able to handle some requests)," read an e-mail from a site spokesman. "We were able to connect to servers in order to reset them. Only rebooting the servers cleared up the issue."

Gawker was at least aware the extra second was coming. "What Are You Going to Do With Your Extra Second?" read a headline on its homepage.

On Friday, with a post to Twitter, Foursquare said its site was down due to the massive outage that hit Amazon's cloud services. But it does not seem that the company has publicly acknowledged a leap second bug.

Marco Marongiu – a senior system administrator with Opera Software, the maker of the Opera browser – discussed the general leap second issue with a blog post dated June 1, providing potential workarounds for the issue. But, as he notes, the leap second problem is nothing new. There have now been more than 25 leap seconds since they were first introduced to atomic clocks in the early 1970s.

In September of last year, with a blog post, Google detailed how it deals with leap seconds. The web giant uses a technique is calls "leap smear," where it gradually adds milliseconds to its system clocks prior to the official arrive of the leap second.

"This meant that when it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day," the company said. "All of our servers were then able to continue as normal with the new year, blissfully unaware that a leap second had just occurred."

On Saturday, many other servers were not so blissfully unaware.

Update: This story has been updated with comment from Gawker and to clarify that the blog post from Opera's Marco Marongiu did not foretell the specific issue that hit systems on Saturday.