default ChronoLocalDateTime<D> minus(long amountToSubtract, 
                                 TemporalUnit unit)

// Java program to demonstrate
// ChronoLocalDateTime.minus() method
  
import java.time.*;
import java.time.chrono.*;
import java.time.temporal.ChronoUnit;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Get the ChronoLocalDateTime instance
        ChronoLocalDateTime ldt
            = LocalDateTime
                  .parse("2019-12-31T19:15:30");
  
        // Get the String representation
        // of this ChronoLocalDateTime
        System.out.println("Original ChronoLocalDateTime: "
                           + ldt.toString());
  
        // subtract 200 DAYS to ChronoLocalDateTime
        ChronoLocalDateTime value
            = ldt.minus(200, ChronoUnit.DAYS);
  
        // print result
        System.out.println("ChronoLocalDateTime after"
                           + " subtracting DAYS: "
                           + value);
    }
}

Original ChronoLocalDateTime: 2019-12-31T19:15:30
ChronoLocalDateTime after subtracting DAYS: 2019-06-14T19:15:30