diff --git a/README.md b/README.md
index 2d0e90c..3ac9fd1 100644
--- a/README.md
+++ b/README.md
@@ -68,9 +68,12 @@ print(df.to_string())
 ```
 or
 ```python
+import datetime as dt
 from bdshare import get_basic_hist_data
 
-df = get_basic_hist_data('2022-03-01','2022-03-02','GP') # get specific instrument data
+start = dt.datetime.now().date() - dt.timedelta(days=2 * 365)
+end = dt.datetime.now().date()
+df = get_basic_hist_data(start, end, 'GP') # get specific instrument data
 print(df.to_string())
 ```
 
@@ -99,9 +102,12 @@ print(df.to_string())
 
 #### Save data to csv file
 ```python
+import datetime as dt
 from bdshare import get_basic_hist_data, Store
 
-df = get_basic_hist_data('2022-03-01','2022-03-02') # get all instrument data
+start = dt.datetime.now().date() - dt.timedelta(days=2 * 365)
+end = dt.datetime.now().date()
+df = get_basic_hist_data(start, end) # get all instrument data
 Store(df).save()
 ```
 
diff --git a/tests/test_trading.py b/tests/test_trading.py
index 4e532db..e893784 100644
--- a/tests/test_trading.py
+++ b/tests/test_trading.py
@@ -15,14 +15,16 @@ def test_get_current_trade_data(self):
         print(df.to_string())
 
     def test_get_market_inf_more_data(self):
+        start = dt.datetime.now().date() - dt.timedelta(days=2 * 365)
         end = dt.datetime.now().date()
-        df = get_market_inf_more_data('2020-01-01', end, index='date')
+        df = get_market_inf_more_data(start, end, index='date')
         print(df.to_string())
         print(df.dtypes)
 
     def test_get_basic_hist_data(self):
+        start = dt.datetime.now().date() - dt.timedelta(days=2 * 365)
         end = dt.datetime.now().date()
-        df = get_basic_hist_data('2020-01-01', end, 'BATBC')
+        df = get_basic_hist_data(start, end, 'BATBC')
         print(df.to_string())
         print(df.dtypes)