Example 1: python date format
%a - Abbreviated weekday name. (Sun, Mon, ...)
%A - Full weekday name. (Sunday, Monday, ...)
%w - Weekday as a decimal number. (0, 1, ..., 6)
%d - Day of the month as a zero-padded decimal. (01, 02, ..., 31)
%-d - Day of the month as a decimal number. (1, 2, ..., 30)
%b - Abbreviated month name. (Jan, Feb, ..., Dec)
%B - Full month name. (January, February, ...)
%m - Month as a zero-padded decimal number. (01, 02, ..., 12)
%-m - Month as a decimal number. (1, 2, ..., 12)
%y - Year without century as a zero-padded decimal number. (00, 01, ..., 99)
%-y - Year without century as a decimal number. (0, 1, ..., 99)
%Y - Year with century as a decimal number. (2013, 2019 etc.)
%H - Hour (24-hour clock) as a zero-padded decimal number. (00, 01, ..., 23)
%-H - Hour (24-hour clock) as a decimal number. (0, 1, ..., 23)
%I - Hour (12-hour clock) as a zero-padded decimal number. (01, 02, ..., 12)
%-I - Hour (12-hour clock) as a decimal number. (1, 2, ... 12)
%p - Locale’s AM or PM. (AM, PM)
%M - Minute as a zero-padded decimal number. (00, 01, ..., 59)
%-M - Minute as a decimal number. (0, 1, ..., 59)
%S - Second as a zero-padded decimal number. (00, 01, ..., 59)
%-S - Second as a decimal number. (0, 1, ..., 59)
%f - Microsecond as a decimal number, zero-padded on the left. (000000 - 999999)
%z - UTC offset in the form +HHMM or -HHMM.
%Z - Time zone name.
%j - Day of the year as a zero-padded decimal number. (001, 002, ..., 366)
%-j - Day of the year as a decimal number. (1, 2, ..., 366)
%U - Week number of the year (Sunday as the first day of the week). All days in a new year preceding the first Sunday are considered to be in week 0. (00, 01, ..., 53)
%W - Week number of the year (Monday as the first day of the week). All days in a new year preceding the first Monday are considered to be in week 0. (00, 01, ..., 53)
%c - Locale’s appropriate date and time representation. (Mon Sep 30 07:06:05 2013)
%x - Locale’s appropriate date representation. (09/30/13)
%X - Locale’s appropriate time representation. (07:06:05)
%% - A literal '%' character. (%)
Example 2: date object into date format python
df['date_column'] = pd.to_datetime(df['date_column'],format='%Y%m%d')