code: def get_start_of_day(year, month, day):
      
      # DST is not known in the provided date
      try:
          timestamp = time.mktime((year, month, day, 00, 00, 00, 0, 0, -1))
      except (OverflowError, ValueError):
          # Windows mktime sometimes crashes on (1970, 1, 1, ...)
          timestamp = 0.0
  
      return int(timestamp)
docs: Get the timestamp associated to the first second of a specific day
  
      :param year: date year
      :type year: int
      :param month: date month
      :type month: int
      :param day: date day
      :type day: int
      :return: timestamp
      :rtype: int