[Bug 31680] Time format (12/24 hour) not adjustable

[JeRa]

Public bug report changed:
https://launchpad.net/malone/bugs/31680

Description changed to:
    I run Ubuntu Dapper. Although I use an English environment, I want
    all my clocks to display the 24-hour time format instead of the
    12-hour AM/PM format.

    I noticed that the login screen showed a 12-hour clock, but I found
    that this could not be changed via System > Administration > Login
    Window. It should be found here, or there should be a dialog which
    controls global time settings.