As some people know, the US Congress mandated new rules for DST (Daylight Savings Time), such that instead of DST starting on the first Sunday in April, it starts on the second Sunday of March. In the fall (or autumn), DST will now end on the first Sunday in November rather than the last Sunday of October.
This has predictably caused a lot of operating systems to update various bits of software to accommodate this change.
On Linux, you just need to upgrade one package (usually called the "timezone" package) and that's it. The rest of the system, and all applications simply use the new information.
Apparently things are not so simple in the so-called "user-friendly" operating system :-)
[ stuff below was extracted from comments in http://lwn.net/Articles/224794/ ]
One comment said:
One thing that surprises me is that, for Microsoft Windows, you don't just need an update patch for the OS, you need patches for applications like Outlook as well. In *nix/Linux systems as far as I'm aware, all the apps just use the common zoneinfo data, so you only need one update for that to fix all your apps. Why doesn't Windows do the same?And here's the explanation from another comment, of which I have extracted the best parts:
Microsoft products tend to do their internal calculations and storage formats in local time. This simplifies display, as there isn't any knowledge of time zone required. That was fine when DOS asked you the current time and date every time you booted, and was *somewhat* liveable after the advent of CMOS clocks. The OS just needed to know what DST algorithm to apply. [...] [But it] also gets weird when you have users from multiple time zones on the same machine.Yet another reason to love Linux -- immune to large doses of whackiness from the US Congress :-)
UNIX and its derivatives tend to do those same things in GMT. This eliminates much of the clock twiddling mess and so on. Also, file date stamps are never ambiguous. What changes is time display. That needs a notion of the current time zone. The plus side is that you can have two dozen users logged in, each in different time zones, and each can see their own local time, just by setting TZ.So if you don't patch Windows, it'll *use* the wrong time. If you don't patch UNIX, it'll just *display* the wrong time.