It seems there have been 34 with serious consequences since 2008. Causes include:

- Omission of an underscore when transcribing an e-mail address led to the wrong subscriber information being provided and a search warrant being executed at the premises of an individual unconnected with the investigation.

- A CSP's data warehouse system change affected how GMT and British Summer Time were treated. This was not communicated to staff using the data retention disclosure system. This led to a one hour error in subscriber information disclosed in relation to IP address usage. Of 98 potential disclosure errors identified, 94 were in fact incorrect and four returned the same results when re-run. Of the 94 incorrect disclosures, in three cases a search warrant was executed at premises relating to individuals unconnected with the investigation (and one individual was arrested).

- Due to a technical fault causing a time zone conversion to be out by seven hours, a CSP voluntarily disclosed an incorrect IP address to a public authority.  That led to a search warrant being executed at premises relating to individuals unconnected with the investigation.

In other words, timezones largely screw up everything, yet again.

Add another one to the "yay for DST" pile. (also yay for AWS using PST/PDT as default internal timezone instead of UTC...)

I have repeatedly been confounded to discover just how many mistakes in both test and application code stem from misunderstandings or misconceptions about time. By this I mean both the interesting way in which computers handle time, and the fundamental gotchas inherent in how we humans have constructed our calendar — daylight savings being just the tip of the iceberg.

In fact I have seen so many of these misconceptions crop up in other people’s (and my own) programs that I thought it would be worthwhile to collect a list of the more common problems here.

See also the follow-up: http://infiniteundo.com/post/25509354022/more-falsehoods-programmers-believe-about-time-wisdom

(via Marc)

'better dates and times for Python', to fix the absurd proliferation of slightly-incompatible Python date/time types and APIs. unfortunately, http://imgs.xkcd.com/comics/standards.png applies....

bookmarking as a future reference

'The Electronic Frontier Foundation (EFF) is pleased to announce that a copyright lawsuit threatening an important database of time zone information has been dismissed. The astrology software company that filed the lawsuit, Astrolabe, has also apologized and agreed to a 'covenant not to sue' going forward, which will help protect the database from future baseless legal actions and disruptions.

Software engineers around the world depend on the time zone database to make sure that time-stamps for email and other files work correctly no matter where you are. However, last September, Astrolabe filed a lawsuit against Arthur David Olson and Paul Eggert – the researchers who coordinated the database's development for decades – because the database includes information from an atlas in which Astrolabe claimed to own copyright. But facts – like what time the sun rises – are not copyrightable. EFF, along with co-counsel Adam Kessel and Olivia Nguyen at the Boston office of Fish & Richardson P.C, promptly signed on to defend Olson and Eggert and protect this essential tool. In January, EFF advised Astrolabe that Olson and Eggert would move for sanctions if Astrolabe did not withdraw its complaint. Today's dismissal followed.'

easy timezone conversion -- bookmarkable URLs, sensible levels of AJAX/JS, nicely done

'a web service of some sort (or any other way) to pull a current time zone settings for a (US) city. For the parts of the country that don't follow the Daylight Saving Time and basically jump timezones when everyone else is switching summer/winter time... I don't fancy creating own database of the places that don't follow DST. Is there a way to pull this data on demand?' earthtools.org seems the closest thing

"Never warp your brain with time zone math again." Quite a useful javascript TZ conversion tool, although it could be more intuitive still