new_contents: # Problem 19 - Counting Sundays
  # You are given the following information, but you may prefer to do some 
  # research for yourself.
  #     1 Jan 1900 was a Monday.
  #     Thirty days has September,
  #     April, June and November.
  #     All the rest have thirty-one,
  #     Saving February alone,
  #     Which has twenty-eight, rain or shine.
  #     And on leap years, twenty-nine.
  #     A leap year occurs on any year evenly divisible by 4, but not on a 
  # century unless it is divisible by 400.
  # How many Sundays fell on the first of the month during the twentieth century 
  # (1 Jan 1901 to 31 Dec 2000)?
  import datetime
  start = datetime.datetime(1901,1,1)
  end = datetime.datetime(2000,12,31)
  numweeks = (end-start).days
  count = 0
  for n in range(numweeks):
      d = start + datetime.timedelta(days=n)
      if d.day == 1 and d.weekday() == 6:
          count += 1
  print(count)
  dates_list = [if (start + datetime.timedelta(days=7*x)).day == 1]
  print(dates_list)
  
subject: Create 19.py