public OffsetDateTime withHour(int hour)

// Java program to demonstrate the withHour() method
  
import java.time.OffsetDateTime;
import java.time.ZonedDateTime;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Parses the date1
        OffsetDateTime date1
            = OffsetDateTime
                  .parse(
                      "2018-12-12T13:30:30+05:00");
  
        // Prints dates
        System.out.println("Date1: " + date1);
  
        // Changes the hour of day
        System.out.println("Date1 after altering hour of the day: "
                           + date1.withHour(20));
    }
}

Date1: 2018-12-12T13:30:30+05:00
Date1 after altering hour of the day: 2018-12-12T20:30:30+05:00

// Java program to demonstrate the withHour() method
  
import java.time.OffsetDateTime;
  
public class GFG {
    public static void main(String[] args)
    {
        try {
            // Parses the date1
            OffsetDateTime date1
                = OffsetDateTime
                      .parse(
                          "2018-12-12T13:30:30+05:00");
  
            // Prints dates
            System.out.println("Date1: " + date1);
  
            // Changes the hour of day
            System.out.println("Date1 after altering hour of the day: "
                               + date1.withHour(27));
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

Date1: 2018-12-12T13:30:30+05:00
Exception: java.time.DateTimeException:
           Invalid value for HourOfDay (valid values 0 - 23): 27