public class GetTiempoGoogle extends AsyncTask<Void, Void, Void> {

    private Context context;
     String dateStr;

    @Override
    protected Void doInBackground(Void... voids) {
        try{
            HttpClient httpclient = new DefaultHttpClient();
            HttpResponse response = httpclient.execute(new HttpGet("https://google.com/"));
            StatusLine statusLine = response.getStatusLine();
            if(statusLine.getStatusCode() == HttpStatus.SC_OK){
                DateFormat df = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss z");
                dateStr = response.getFirstHeader("Date").getValue();
                Date startDate = df.parse(dateStr);
                dateStr = String.valueOf(startDate.getTime()/1000);
                //Here I do something with the Date String

            } else{
                //Closes the connection.
                response.getEntity().getContent().close();
                throw new IOException(statusLine.getReasonPhrase());
            }
        }catch (ClientProtocolException e) {
            Log.d("Response", e.getMessage());
        }catch (IOException e) {
            Log.d("Response", e.getMessage());
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
    // can use UI thread here
    protected void onPostExecute(String dateStr) {



    }

    public String getDateStr() {
        return dateStr;
    }
}

GetTiempoGoogle Uconexion = new GetTiempoGoogle();
        Uconexion.execute();
        String Uconexionapp = Uconexion.getDateStr();
        Log.e("UconexionApp",""+Uconexionapp);