infer_datetime_format : boolean, default False
如果设定为True并且parse_dates 可用，那么pandas将尝试转换为日期类型，如果可以转换，转换方法并解析。在某些情况下会快5~10倍。

import pandas as pd

df = pd.read_excel('data2.xlsx')
print(df['Posting Date'].head())
df['Posting Date'] = pd.to_datetime(
    df['Posting Date'], infer_datetime_format=True)
print(df['Posting Date'].head())
df.to_excel(excel_writer='data2_V1.xlsx')

使用dt.strfdate（）

import pandas as pd

df = pd.read_excel('data2.xlsx')
print(df['Posting Date'].head())
df['Posting Date'] = pd.to_datetime(
    df['Posting Date'], infer_datetime_format=True)
print(df['Posting Date'].head())
df['Posting Date'] = df['Posting Date'].dt.strftime("%Y-%m-%d")
print(df['Posting Date'].head())
df.to_excel(excel_writer='data2_V3.xlsx')