ValueError: zero length field name in format

ValueError: zero length field name in format

I am trying to convert date to a nice format using below code and
runninginto following error..can anyone provide inputs on how to overcome
here?
from datetime import datetime
d = datetime.fromtimestamp(1372058963)
print d
create_date = datetime.strptime(str(d), '%Y-%m-%d %H:%M:%S')
print create_date
gerrit_created_date =
"{}/{}/{}".format(create_date.month,create_date.day,create_date.year)
print gerrit_created_date
Error:-
File "test.py", line 7, in <module>
gerrit_created_date =
"{}/{}/{}".format(create_date.month,create_date.day,create_date.year)
ValueError: zero length field name in format