GetBarOffset 使用問題

我用以下程式碼想得到 2020/1/20 收盤價

先用 value1 變數取得與現在差幾天

再用 value4=close[value1]; 取得該天收盤價

程式執行 value1=3 , 應該是 22 才正確 , 我哪裡寫錯了 

SetTotalBar(3);

Value1 = GetBarOffset(20200120);
value2 = close[22];
//Value3 = close;
value4 = close[value1];

OutputField1(value2,2,"1/20收盤價");
//OutputField2(value3,2,"最近收盤價");
OutputField3(value1,2,"value1");
OutputField4(value4,2,"1/20收盤價2");

ret=1;