Python project - Find mean of day only from a list of dates

I need a function to extract days from a column in a dataframe, and then from the days, find the mean date.
exemple :
We have 3 dates
12/03/2022
14/04/2022
13/05/2022
Output : 13

another exemple :
30/01/2022
02/03/2022
29/03/2022
Output 2.5