import pytz


def GetDatetimeInTimezone(timezone_name, date_time):
  """Returns the datetime.datetime of the given one in the specified timezone.

  Args:
    timezone_name (str): The name of any timezone supported by pytz.
    date_time (datetime.datetime): The optional datetime to be converted into
        the new timezone.

  Returns:
    A datetime.datetime of the given one in the specified timezone.
  """
  return date_time.astimezone(pytz.timezone(timezone_name))