Różnica pand między datami
# credit to Stack Overflow user in the source link
import pandas as pd
# df is your pandas dataframe
# if already datetime64 you don't need to use to_datetime
df['A'] = pd.to_datetime(df['A'])
df['B'] = pd.to_datetime(df['B'])
df['diff'] = df['A'] - df['B'] # difference in days
wolf-like_hunter