I would like to create an algorithm that searches for **decades **and not specific years.

For example, the 80s should return movies released in 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988 and 1989, totaling 10 years.

I have written about three different algorithms and they never work, they always return a specific year in the API.

Is this an API limitation or my stupidity?

Some code I tried:

<optgroup label="Décadas">
                      {Array.from({ length: 10 }, (_, i) => {
                        const decade = Math.floor(new Date().getFullYear() / 10) * 10 - i * 10;
                        return (
                          <option key={`decade-${decade}`} value={`${decade}`}>
                            Década de {decade}
                          </option>
                        );
                      })}
 </optgroup>

export function getDecadeRange(decade: string): { startYear: string; endYear: string } {
  // Verificar se é um valor de década (30, 40, etc) ou um ano específico (1977, 2022, etc)
  // Décadas são representadas por 2 dígitos
  if (decade.length === 2) {
    const decadeNum = parseInt(decade, 10);
    // Para décadas do século 20 (antes de 2000)
    if (decadeNum < 20) { // Assumindo que décadas de 00-19 são do século 21
      return {
        startYear: `20${decade}`, // ex: 00 -> 2000
        endYear: `20${decade}9`   // ex: 00 -> 2009
      };
    } else {
      return {
        startYear: `19${decade}`, // ex: 90 -> 1990
        endYear: `19${decade}9`   // ex: 90 -> 1999
      };
    }
  }

If I choose 70s, the API returns "year": "1970", and it should return "year": "1970, 1971, 1972...",