minusHours() method of a ZonedDateTime class used to subtract the number of hours from this ZonedDateTime and return a copy of ZonedDateTime after subtraction.This operates on the instant time-line, such that subtracting one hour will always be a duration of one hour earlier. subtracting one hour may cause the local date-time to change by an amount other than one hour.
For example, consider a time-zone, such as ‘Europe/Paris’, where the Autumn DST cutover means that the local times 02:00 to 02:59 occur twice changing from offset +02:00 in summer to +01:00 in winter.
- Subtracting one hour from 03:30+01:00 will result in 02:30+01:00 (both in winter time)
- Subtracting one hour from 02:30+01:00 will result in 02:30+02:00 (moving from winter to summer time)
- Subtracting one hour from 02:30+02:00 will result in 01:30+02:00 (both in summer time)
- Subtracting three hours from 03:30+01:00 will result in 01:30+02:00 (moving from winter to summer time)
This instance is immutable and unaffected by this method call.
Syntax:
public ZonedDateTime minusHours(long hours)
Parameters: This method accepts a single parameter hours which represents the hours to subtract, It can be negative.
Return value: This method returns a ZonedDateTime based on this date-time with the hours subtracted.
Exception: This method throws DateTimeException if the result exceeds the supported date range.
Below programs illustrate the minusHours() method:
Program 1:
// Java program to demonstrate// ZonedDateTime.minusHours() method  import java.time.*;  public class GFG {    public static void main(String[] args)    {          // create a ZonedDateTime object        ZonedDateTime zoneddatetime            = ZonedDateTime.parse(                "2018-12-06T19:21:12.123+05:30[Asia/Calcutta]");          // print instance        System.out.println("ZonedDateTime before"                           + " subtracting hours: "                           + zoneddatetime);          // subtract 3 hours        ZonedDateTime returnvalue            = zoneddatetime.minusHours(3);          // print result        System.out.println("ZonedDateTime after "                           + " subtracting 3 hours: "                           + returnvalue);    }} |
ZonedDateTime before subtracting hours: 2018-12-06T19:21:12.123+05:30[Asia/Calcutta]
ZonedDateTime after subtracting 3 hours: 2018-12-06T16:21:12.123+05:30[Asia/Calcutta]
Program 2:
// Java program to demonstrate// ZonedDateTime.minusHours() method  import java.time.*;  public class GFG {    public static void main(String[] args)    {          // create a ZonedDateTime object        ZonedDateTime zoneddatetime            = ZonedDateTime.parse(                "2018-10-25T23:12:31.123+02:00[Europe/Paris]");          // print instance        System.out.println("ZonedDateTime before"                           + " subtracting hours: "                           + zoneddatetime);          // subtract 20 hours        ZonedDateTime returnvalue            = zoneddatetime.minusHours(20);          // print result        System.out.println("ZonedDateTime after "                           + " subtracting 20 hours: "                           + returnvalue);    }} |
ZonedDateTime before subtracting hours: 2018-10-25T23:12:31.123+02:00[Europe/Paris]
ZonedDateTime after subtracting 20 hours: 2018-10-25T03:12:31.123+02:00[Europe/Paris]
Reference: https://docs.oracle.com/javase/10/docs/api/java/time/ZonedDateTime.html#minusHours(long)
