The file_date function creates a new file in the current working directory, checks the date that the file was modified, and returns just the date portion of the timestamp in the format of yyyy-mm-dd.

file_timestamp.py

def file_date(filename):
  # Create the file in the current directory
  # For mknod the root priveleges are required
  os.mknod(filename)
  timestamp = os.path.getmtime(filename)
  # Convert the timestamp into a readable format, then into a string
  time = datetime.datetime.fromtimestamp(timestamp)
  time = str(time)
  # Return just the date portion 
  # Hint: how many characters are in “yyyy-mm-dd”? 
  return ("{:.10s}".format(time))

print(file_date("newfile.txt"))