On Sun, Dec 13, 2015 at 5:00 PM, James K. Lowden <jklowden at schemamania.org> wrote:
> On Thu, 10 Dec 2015 06:34:44 -0700 > "Keith Medcalf" <kmedcalf at dessus.com> wrote: > > > The only way to convert datetime data on windows is to use a > > third-party package that does it properly, or write it yourself. > > Using the WinAPI functions is equivalent to "writing it yourself" > > because they do not actually do anything -- you have to manage all > > the meaningful data and deal with the vagaries of the > > under-documented closed proprietary function implementations in > > windows (which Microsoft even admits do not work properly). > > Keith, your answer was so disheartening that I was impelled to revisit > where the C standard is on time zones. I remembered it was messy, but > thought it had surely been fixed. > > It's not fixed, although gacial progress is being made. Even though > we've had the TZ database & Posix datetime functions since 1986, 30 > years later we're still struggling with it, and not only on Windows. > The problem would be that SQLite could not depend on the presence of TZ functions even if they were added to the standard: 1. SQLite generally avoids non ANSI C so as to be compatible with the largest possible number of platforms. ANSI C (aka C89 or C90 for the ISO version) will never be updated to add new requirements. 2. Let's say that that the next version of the C standard does add TZ functionality. That functionality would almost certainly only be required for hosted implementations. Freestanding implementations have a much smaller set of requirements (they don't even require the *current* time functions!), and are the types of implementations used in targeting all these embedded devices that make SQLite (likely) the most deployed software in the world. -- Scott Robison
