public Instant minusMillis(long millisToSubtract)

// Java program to demonstrate
// Instant.minusMillis() method
  
import java.time.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a Instant object
        Instant instant
            = Instant.parse("2018-12-30T19:34:50.63Z");
  
        // subtract 64000000 MILLI_OF_SECOND
        // means 64000 seconds from this instant
        Instant returnedValue
            = instant.minusMillis(64000000);
  
        // print result
        System.out.println("Returned Instant: "
                           + returnedValue);
    }
}

Returned Instant: 2018-12-30T01:48:10.630Z

// Java program to demonstrate
// Instant.minusMillis() method
  
import java.time.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a Instant object
        Instant instant = Instant.now();
  
        // current Instant
        System.out.println("current instant: "
                           + instant);
  
        // subtract 36000000 MILLI_OF_SECOND
        // means 36000 seconds from this instant
        Instant returnedValue
            = instant.minusMillis(36000000);
  
        // print result
        System.out.println("Returned Instant: "
                           + returnedValue);
    }
}

current instant: 2018-11-27T05:13:12.132Z
Returned Instant: 2018-11-26T19:13:12.132Z