I modified the "format_utcoffset" function in "_datetimemodule.c", to accept one more parameter "secondsrequired" . It is a boolean variable (PyObject) , which when set to true, the function will return the offset formatted as "+HH:MM:SS" or "-HH:MM:SS". I also modified the "wrap_strftime" function to also accept the strings "%:z" and "%::z" as format specifiers. This is my first contribution to python , so my approach of modifying a function's default parameters might not be correct. Any help is appreciated 
Thanks