def get_day_name(day_no):
    """
    Returns the full name of the day in the week.
    :param day_no: The number of day to convert.
    :return: Full name of day in the week.
    """
    if day_no == 1:
        return "Monday"
    elif day_no == 2:
        return "Tuesday"
    elif day_no == 3:
        return "Wednesday"
    elif day_no == 4:
        return "Thursday"
    elif day_no == 5:
        return "Thursday"
    elif day_no == 6:
        return "Saturday"
    elif day_no == 7:
        return "Sunday"

    return "NOT_RECOGNIZED"