a vocabulary text day trick ?

     static String days[]={"SUNDAY","MONDAY","TUESDAY","WEDNESDAY","THUSDAY","FRIDAY","SATURDAY"};

    

    static Hashtable<String,Integer>hash=new Hashtable<>();

    static{

        int i=0;

        while(i<days.length){

            hash.put(days[i].substring(0,2),i);

            ++i;

        }

    }

    public static void main(String[] args) {

        

        int i=0;

        int l=10000000;

        int r,o;

        

        long ts=System.currentTimeMillis();

        while(i<l){

            r=Rand.sti.nextInt(7);

            o=getIndexOfDay0(days[r]);

            ++i;

        }

        long te=System.currentTimeMillis();

        te-=ts;

        System.out.println("time:"+te);

    }

    static final int[]trick0={

        4,6,5,0,0

       ,3,0,0,0,0

       ,0,0,0,1,0

       ,0,0,0,0,0

       ,2

    } ;

    

    public static int getIndexOfDay1(String someday){

        String key=Character.toUpperCase(someday.charAt(0))+""+Character.toUpperCase(someday.charAt(1));

        return hash.get(key);

    }

    public static int getIndexOfDay0(String someday){

        char ch0=Character.toUpperCase(someday.charAt(0));

        int ch1=Character.toUpperCase(someday.charAt(1));

        ch1&=ch0;

        ch1-=64;

        return trick0[ch1];

    }