Getting the min value of a date in Pandas

October 18, 2022

I have this df

Start_Time  
0   18/08/2022 00:04:44 
1   18/08/2022 00:09:54 
2   18/08/2022 00:13:00 
3   18/08/2022 00:16:09 
4   18/08/2022 00:18:10

and I’m trying to get the minimum Start_time value, it can be YYYY/MM/DD or DD/MM/YYYY

this is the piece of code I’m using :

df_test['Start_time'] = pd.to_datetime(df_test['Start_time'])

and then trying to get the min value

df_test['MIN_Start_time'] = df_test['Start_time'].dt.strftime('%Y/%m/%d').min()

that’s the output of my code, but it should give me as MIN_start_time the value 2022/08/18 or 18/08/2022

Start_Time  MIN_Start_time
0   18/08/2022 00:04:44 2022/01/09  
1   18/08/2022 00:09:54 2022/01/09  
2   18/08/2022 00:13:00 2022/01/09  
3   18/08/2022 00:16:09 2022/01/09  
4   18/08/2022 00:18:10 2022/01/09

Any ides what I’m doing wrong?

>Solution :

df['Start_Time']=pd.to_datetime(df['Start_Time'], dayfirst=True)

df['min_start_date']=df['Start_Time'].min()
df

Start_Time  min_start_date
0   2022-08-18 00:04:44     2022-08-18 00:04:44
1   2022-08-18 00:09:54     2022-08-18 00:04:44
2   2022-08-18 00:13:00     2022-08-18 00:04:44
3   2022-08-18 00:16:09     2022-08-18 00:04:44
4   2022-08-18 00:18:10     2022-08-18 00:04:44

to get just the date part

df['min_start_date']=df['Start_Time'].dt.strftime('%F').min()
df

df['min_start_date']=df['Start_Time'].dt.date.min()
df

    Start_Time  min_start_date
0   2022-08-18 00:04:44     2022-08-18
1   2022-08-18 00:09:54     2022-08-18
2   2022-08-18 00:13:00     2022-08-18
3   2022-08-18 00:16:09     2022-08-18
4   2022-08-18 00:18:10     2022-08-18