Change this
EditText etDate = (EditText) findViewById(R.id.SSA_ETDate);
to
etDate = (EditText) findViewById(R.id.SSA_ETDate);
You already have
EditText etDate; // declared but not initialized
But in onCreate
you again declare and then initialize
EditText etDate = (EditText) findViewById(R.id.SSA_ETDate);
//etDate is local to onCreate
Similarly for other variables
btnAdd = (Button) findViewById(R.id.SSA_BtnAdd);
tv1 = (TextView) findViewById(R.id.SSA_Tv1);
etDate = (EditText) findViewById(R.id.SSA_ETDate);