LocalDateTime не могу понять, как задать период времени

package model;
 
import java.time.LocalDate;
import java.time.LocalDateTime;
 
public class Client{
    private final LocalDateTime up = LocalDateTime.now();
    private String fName;
    private String sName;
    private LocalDate burnDate;
    private LocalDateTime registedDate;
    private FitnessServiceEnumeration clientStatus;
 
    public Client(String fName, String sName, LocalDate burnDate) {
        this.fName = fName;
        this.sName = sName;
        this.burnDate = burnDate;
        this.registedDate = LocalDateTime.now();
    }
 
    public Client(String fName, String sName, LocalDate burnDate, LocalDateTime registedDate) {
        this.fName = fName;
        this.sName = sName;
        this.burnDate = burnDate;
        this.registedDate = registedDate;
    }
 
    public void setfName(String fName) {
        this.fName = fName;
    }
 
    public void setsName(String sName) {
        this.sName = sName;
    }
 
    public void setBurnDate(LocalDate burnDate) {
        this.burnDate = burnDate;
    }
 
    public String getfName() {
        return fName;
    }
 
    public String getsName() {
        return sName;
    }
 
    public LocalDate getBurnDate() {
        return burnDate;
    }
 
    public LocalDateTime getRegistedDate() {
        return registedDate;
    }
 
    public FitnessServiceEnumeration getClientStatus() {
        return clientStatus;
    }
 
    public void setClientStatus(FitnessServiceEnumeration clientStatus) {
    //    LocalDate localDate = LocalDate.from(getRegistedDate());
       // LocalDateTime limit = lo
        //if (getRegistedDate().isAfter())
        if (clientStatus == FitnessServiceEnumeration.GROUP) {
            throw new IllegalArgumentException(" Illegal Argumen tException");
        } else {
            this.clientStatus = clientStatus;
        }
    }
 
    @Override
    public String toString() {
        return String.format("Name: %s %s \nBurn date: %s \nClient on %s", getfName(),
                getsName(),
                getClass(),
                getClientStatus());
    }
}

LocalTime start = LocalTime.of(8, 0);
LocalTime end = LocalTime.of(20, 0);
 
LocalTime time1 = LocalTime.of(20, 20);
LocalTime time2 = LocalTime.of(15, 20);
 
System.out.println(time1.isAfter(start) && time1.isBefore(end));
System.out.println(time2.isAfter(start) && time2.isBefore(end));