get all friday by python.

getAllFriday.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
from datetime import date, timedelta as td

d1 = date(2015, 1, 2)
d2 = date(2016, 12, 31)

delta = d2 - d1

for i in range(0, delta.days + 1, 7):
    print d1 + td(days=i)