input_formats
A list of formats used to attempt to convert a string to a valid datetime.date object.
If no input_formats argument is provided, the default input formats are:
['%Y-%m-%d', # '2006-10-25'
'%m/%d/%Y', # '10/25/2006'
'%m/%d/%y'] # '10/25/06'
Additionally, if you specify USE_L10N=False in your settings, the following will also be included in the default input formats:
['%b %d %Y', # 'Oct 25 2006'
'%b %d, %Y', # 'Oct 25, 2006'
'%d %b %Y', # '25 Oct