获取当前日期最初、最末时刻

public static Date setTimeStart(Date date) {
        if (date == null)
            return null;
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.set(Calendar.HOUR_OF_DAY, 0);
        c.set(Calendar.MINUTE, 0);
        c.set(Calendar.SECOND, 0);
        return c.getTime();
    }

    public static Date setTimeEnd(Date date) {
        if (date == null)
            return null;
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.set(Calendar.HOUR_OF_DAY, 23);
        c.set(Calendar.MINUTE, 59);
        c.set(Calendar.SECOND, 59);
        return c.getTime();
    }