why is there a new date out of my data range after resample in python

Question

my max and min date are 2023-04-21 00:00:00 and 2023-04-01 00:00:00, a three weeks range beginning at Saturday.
`

        df = pd.read_csv(file, usecols=['distance', 'class_index', 
    '   date'])
        df['date'] = pd.to_datetime(df['date'])
        max_date = df['date'].max()
        min_date = df['date'].min()
        print(f"{max_date}")
        print(f"{min_date}")

        df.set_index('date', inplace=True)
        weekly_avg = df.groupby('class_index').resample('W', 
        closed='right',
                                                         
        loffset=pd.DateOffset(days=-1)).mean()`

---

and my result is：

       distance  class_index
class_index date                                  
0.0         2023-04-01      16.472320          0.0
            2023-04-08      18.160144          0.0
            2023-04-15      19.178941          0.0
            2023-04-22      20.124844          0.0
1.0         2023-04-01       9.559542          1.0
            2023-04-08      10.213785          1.0
            2023-04-15      10.849616          1.0
            2023-04-22      11.068927          1.0

why 2023-4-22 is there？

my expectation1 is：

    distance  class_index
class_index date                                  
0.0         2023-04-01      16.472320          0.0
            2023-04-08      18.160144          0.0
            2023-04-15      19.178941          0.0
1.0         2023-04-01       9.559542          1.0
            2023-04-08      10.213785          1.0
            2023-04-15      10.849616          1.0