The withHour() method of OffsetDateTime class in Java returns a copy of this OffsetDateTime with the hour of the day altered as specified in the parameter.
Syntax:
public OffsetDateTime withHour(int hour)
Parameter: This method accepts a single parameter hour which specifies the hour of the day to be set in the result which can range from 0 to 23.
Return Value: It returns a OffsetDateTime based on this date with the requested hour of the day and not null.
Exceptions: The program throws a DateTimeException when the hour of the day value is invalid or if the day-of-year is invalid.
Below programs illustrate the withHour() method:
Program 1:
// 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));    }} |
Output:
Date1: 2018-12-12T13:30:30+05:00 Date1 after altering hour of the day: 2018-12-12T20:30:30+05:00
Program 2:
// 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);        }    }} |
Output:
Date1: 2018-12-12T13:30:30+05:00
Exception: java.time.DateTimeException:
Invalid value for HourOfDay (valid values 0 - 23): 27
Reference: https://docs.oracle.com/javase/10/docs/api/java/time/OffsetDateTime.html#withHour(int)
