不选“使用24小时格式”以后，状态栏不会显示“上午”和“下午”

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/Clock.java

    private static final int AM_PM_STYLE_NORMAL  = 0;
    private static final int AM_PM_STYLE_SMALL   = 1;
    private static final int AM_PM_STYLE_GONE    = 2;

    private static final int AM_PM_STYLE = AM_PM_STYLE_NORMAL;  //jeff. AM_PM_STYLE_GONE;