import java.time.*;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String args[]) {
        var strDateTime = "Mon, 11 Sep 2023 15:49:32 GMT";

        // Use a ZoneOffset as desired e.g. ZoneOffset.of("+05:00");
        var zoneOffset = ZoneOffset.UTC;

        var dateFrom = OffsetDateTime.parse(strDateTime, DateTimeFormatter.RFC_1123_DATE_TIME)
                .withOffsetSameInstant(zoneOffset)
                .toLocalDate();
        var dateUntil = LocalDate.now(zoneOffset);
        var period = Period.between(dateFrom, dateUntil);
        System.out.println(period);

        // Formatted
        System.out.println(formattedPeriod(period));
    }

    static String formattedPeriod(Period period) {
        var years = period.getYears();
        var months = period.getMonths();
        return years > 0 ? years + " years" : months > 0 ? months + " months" : period.getDays() + " days";
    }
}