Public holidays in the Netherlands - Liberation Day about holiday HOT 3 CLOSED

public static DateTime? LiberationDay(int year)
       {
           if (year < 1990 && year % 5 == 0)
           {
               return new DateTime(year, 5, 5);
           }

           return new DateTime(year, 5, 5);
       }

public static DateTime? LiberationDay(int year)
        {
            if (year >= 1990)
            {
                return new DateTime(year, 5, 5);
            }
            else if (year >= 1945)
            {
                if (year % 5 == 0)
                {
                    return new DateTime(year, 5, 5);
                }
            }
           return null;
        }